concatenating the rows to have a column wise data

In the attached data set, the rows provide daily information at a fifteen minute interval for a set of 9 variables for 31 days of January. Is there an easy way to rearrage this data, so I have 9 variables as columns and their sequence of observations for the entire month as rows. Please help!

Answer 1

[DGM]

This could almost certainly be simplified, but I think this is at least readable:

% data arranged as groups of 4 row vectors
A = [1:10; 101:110; 201:210; 301:310; 11:20; 111:120; 211:220; 311:320]

A = 8×10

1 2 3 4 5 6 7 8 9 10 101 102 103 104 105 106 107 108 109 110 201 202 203 204 205 206 207 208 209 210 301 302 303 304 305 306 307 308 309 310 11 12 13 14 15 16 17 18 19 20 111 112 113 114 115 116 117 118 119 120 211 212 213 214 215 216 217 218 219 220 311 312 313 314 315 316 317 318 319 320

% rearrange
B = [reshape(A(1:4:end,:).',[],1) ...
    reshape(A(2:4:end,:).',[],1) ...
    reshape(A(3:4:end,:).',[],1) ...
    reshape(A(4:4:end,:).',[],1)]

B = 20×4

1 101 201 301 2 102 202 302 3 103 203 303 4 104 204 304 5 105 205 305 6 106 206 306 7 107 207 307 8 108 208 308 9 109 209 309 10 110 210 310

The webpage truncates the final output here, but it does continue in a column vector format.

[Kushal Bhalla]

Vow! This is amazing. I am elated. Such a succinct and an ingenious way of reorganizing data. Absolutely liked ur response, illustration, and solution. This really addresses my problem completely. I had been struggling with long pieces of code to reach the same endpoint. Sir, you have done it in just few lines of code. Excellent! Great! Really appreciate!

[Kushal Bhalla]

Sir,

I had been trying to use your code to the attached data set. In order to get only the table values, I had deleted the first row and also the first column. However, I am getting the following error:

"Undefined function 'transpose' for input arguments of type 'table'. Use the ROWS2VARS function instead."

Could you please have a look.

Thanks

[DGM]

Afaik, operations like transpose(), reshape() don't work on tables. In the given example, they're just working on numeric arrays.

A = readmatrix('data.csv'); % read into a numeric array
A = A(:,2:end); % changed

cols = 9; % number of output columns
A = reshape(A.',size(A,2),cols,[]);
A = permute(A,[1 3 2]);
A = reshape(A,[],cols)

A = 2976×9

1.0e+03 * 0.0083 2.5167 0.1137 1.4888 0.0077 0.9481 0.0045 0 1.5426 0.0076 2.4847 0.1129 1.4897 0.0074 0.9485 0.0045 0 1.5551 0.0073 2.4823 0.1155 1.5114 0.0074 0.9483 0.0045 0 1.5129 0.0073 2.4699 0.1146 1.4869 0.0074 0.9485 0.0044 0 1.5282 0.0073 2.4487 0.1144 1.4784 0.0073 0.9486 0.0045 0 1.5053 0.0074 2.4417 0.1142 1.4680 0.0073 0.9485 0.0044 0 1.4814 0.0078 2.3994 0.1122 1.4474 0.0073 0.9483 0.0045 0 1.5047 0.0080 2.3620 0.1124 1.4751 0.0073 0.9484 0.0045 0 1.4768 0.0082 2.3483 0.1120 1.4686 0.0073 0.9482 0.0044 0 1.4545 0.0080 2.2819 0.1121 1.4672 0.0073 0.9482 0.0043 0 1.4772

[Kushal Bhalla]

Sir,

31 * 96 = 2976. Therefore, ''A'' should be 2976 * 9. How come we got 2852 * 9?

We can get rid of the first column which is more like an id. The first row serves as a header. Perhaps that is required. Isn't it?

Apart from these all other entries can be kept the way they are.

A question about, A = A(:,2:end-4)......here are we getting rid of some columns? If NaNs appear as an observation value then we may keep it to be handled later on.

Thanks

Appreciate your help!

[DGM]

Oh that's just great. The behavior of readmatrix() differs between versions, so it returns a different size output than I was getting. That's why it's wrong. I'll fix it in a minute.

There is one column denoting date and category. There are four trailing columns containing empty chars. When converted to numeric, all five of these columns will become NaN. In R2019b, all five columns are preserved. In R2023b, apparently only some of them are. The trailing columns get discarded in the newer version, so attempting to discard them manually was truncating the data.

[Kushal Bhalla]

Great! This ran well.

Sir, I have another dataset jan13.xlsx (attached). It has one additional column of total. I tried to change the code to get rid of that as follows (starting from 3 instead of 2):

A = readmatrix('jan13.xlsx'); % read into a numeric array
A = A(:,3:end); % changed
cols = 9; % number of output columns
A = reshape(A.',size(A,2),cols,[]);
A = permute(A,[1 3 2]);
A = reshape(A,[],cols)

but got the following error message:

Error using reshape

Product of known dimensions, 864, not divisible into total number of elements, 26880.

Error in (line 4)

A = reshape(A.',size(A,2),cols,[]);

[DGM]

readmatrix() is picking up the time headers as data, so row 1 needs to be omitted.

A = A(2:end,3:end); 

Stuff like readmatrix() and readtable() might be conveniences, but it pays to make sure it's picking up the file like you expect.

[Kushal Bhalla]

Great Sir! this worked.

Sir, in another dataset (attached) the same information (biomass, coal, gas, gas cc, hydro, nuclear, other, solar, wind) is presented in a different manner (days for each fuel clubbed separately). However, I am interested in the same final output of 9 columns and 2976 rows. Could you please have a look? Shall be grateful for your help.

Answer 2

[Stephen23]

The MATLAB approach:

T = readtable('data.csv', 'VariableNamingRule','Preserve')

T = 279×97 table
         Date-Fuel           0:15      0:30      0:45      1:00      1:15      1:30      1:45      2:00      2:15      2:30      2:45      3:00      3:15      3:30      3:45      4:00      4:15      4:30      4:45      5:00      5:15      5:30      5:45      6:00      6:15      6:30      6:45      7:00      7:15      7:30      7:45      8:00      8:15      8:30      8:45      9:00      9:15      9:30      9:45     10:00     10:15     10:30     10:45     11:00     11:15     11:30     11:45     12:00     12:15     12:30     12:45     13:00     13:15     13:30     13:45     14:00     14:15     14:30     14:45     15:00     15:15     15:30     15:45     16:00     16:15     16:30     16:45     17:00     17:15     17:30     17:45     18:00     18:15     18:30     18:45     19:00     19:15     19:30     19:45     20:00     20:15     20:30     20:45     21:00     21:15     21:30     21:45     22:00     22:15     22:30     22:45     23:00     23:15     23:30     23:45      0:00 
    ____________________    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______    ______

    {'01/01/12-Biomass'}       8.3      7.61      7.32      7.32      7.32      7.43      7.83      7.98      8.19      7.97      7.31      7.63      7.94      8.04      8.23      8.13      8.14      8.14      8.08      7.78      7.79       7.8      7.78       7.8      7.86      7.86      7.88      7.88      7.87      7.87      7.84      7.87      7.86      7.72      6.92      6.96      6.96      6.95      6.95      6.96      6.92      6.69      6.55      6.92      7.76      7.91       7.9      7.92       7.9      7.95      8.02      8.21      8.35      8.36      8.35      8.37      8.35      8.36      8.27      8.34      8.34      8.35      7.76       7.7      7.74      7.77      8.03      8.14      8.07      8.08      8.08       7.9      7.77      7.79      7.81      7.82       7.9      8.07      8.23       8.3      8.39      8.39      8.39      8.39      8.38      8.39      8.35      8.31      8.29      8.18      8.16      8.15      8.16      8.15      8.15      8.16
    {'01/01/12-Coal'   }    2516.7    2484.7    2482.2    2469.9    2448.7    2441.7    2399.4      2362    2348.3    2281.9    2267.7    2260.9    2303.9    2364.2    2391.6    2418.5    2440.7    2454.6    2483.8    2493.2    2551.9    2590.1    2607.8    2612.4    2628.5    2658.9    2699.8    2768.6    2838.6    2865.1    2882.2    2868.2    2877.2    2905.7    2939.3    2984.7    3025.6    3093.7    3158.1    3189.4    3201.1    3181.6    3159.8    3171.9    3216.9    3285.5    3316.5    3314.4    3335.3      3355    3360.7    3367.1    3351.9    3335.1      3320    3286.9      3249    3217.2    3164.1    3101.4    3062.4    3065.1    3058.8    3040.2    3014.3    2999.9    2993.9    3007.4    3027.6    3075.6    3149.7    3294.8    3431.3      3550    3624.3    3661.5    3665.4    3671.4    3672.8    3683.8    3673.3    3656.4    3631.7    3600.6    3600.6    3599.9    3585.5    3563.5      3523    3472.7    3417.7    3371.5    3343.4    3306.1    3221.7    3155.8
    {'01/01/12-Gas'    }    113.68    112.89    115.51    114.61    114.45    114.15    112.18    112.38    111.97    112.09    111.97    112.01    113.25    115.19     114.8    113.99    114.09    114.49    114.63    114.73    114.86    114.69    114.95     115.5    124.97       129    130.38    130.69    131.64    132.81    137.65     160.1    162.15    163.01    162.42    162.04     161.6    161.04    160.67    158.79    157.86    157.65     157.8    157.83    158.05    157.99    157.55    157.49    156.33     151.3    141.53    132.57    129.07    128.82     131.3    148.69    149.75     130.9    130.71    131.19    130.65    130.58    131.18    132.23    132.27    132.32    132.75     131.9    132.75    133.04    133.19    137.81    137.81    137.72    138.06    139.51    139.78    140.74    140.51    140.09    138.53    135.05    135.01    134.71    134.74    135.24    135.03    135.18    129.49     124.3    125.63    125.51    125.63    125.77     126.2    126.42
    {'01/01/12-Gas_CC' }    1488.8    1489.7    1511.4    1486.9    1478.4      1468    1447.4    1475.1    1468.6    1467.2    1464.5    1489.3    1528.5    1507.1    1498.4    1486.8    1467.1    1494.8    1461.7    1479.7    1529.7      1522    1524.3    1524.6    1544.5    1581.1    1653.4    1724.7    1776.8    1794.6    1825.1    1830.7    1875.5    1924.3    1996.8    2089.6    2194.3    2236.3    2243.1    2235.5    2236.4    2232.1    2251.2    2272.3    2297.8    2305.8    2316.3    2337.8    2343.7    2332.9    2335.6    2326.9    2308.9    2304.9    2305.4    2292.9    2300.4      2296    2298.6    2323.6    2332.3    2342.2    2343.3    2352.4      2383    2413.1    2440.1    2482.3    2572.6    2668.6    2828.8      2980    3052.5    3040.1    3017.8    3008.2    3029.7    3026.1    3012.2    2963.9    2947.9      2940    2926.2    2922.9    2923.5    2897.3    2878.5    2853.8    2821.1    2808.2    2794.9      2773    2705.9    2633.7    2614.4      2592
    {'01/01/12-Hydro'  }      7.67      7.37      7.38      7.37      7.35      7.34      7.34      7.35      7.34      7.34      7.35      7.34      7.33      7.33      7.32      7.32      7.33      7.32      7.32      7.32      7.53      7.68       7.9      7.93     10.26     10.42     10.39     10.12      8.41      8.38      8.38      8.41      8.42      8.46      8.44      8.46      8.45      8.45      8.44      8.45      8.45      8.47      8.47      8.49      7.97      7.64      7.65      7.63      7.42       7.4      7.41      7.41      7.41      7.43      7.42      7.44      7.42      7.43      7.42      7.41      7.42      7.41      7.41      7.42      7.41      7.41      7.41      7.47     12.73     13.04     13.08     13.26     21.69     27.86     29.84     29.95     16.21     16.23     16.22     16.23     16.23     16.24     16.23     16.23     16.21     16.23     16.21     16.22     16.24     16.22     16.22     16.22     16.13     16.25     16.26     16.25
    {'01/01/12-Nuclear'}    948.15    948.48    948.29    948.51    948.55    948.45     948.3    948.41    948.19    948.16    948.24    948.25    948.18    948.15    948.23    947.98    948.19    948.25    948.35    948.32    948.27    948.28    948.26    948.29    948.35    948.32    948.28    948.29    948.32    948.31    948.44    948.53    948.56    948.64    948.64    948.78    948.64    948.73    948.84    948.87    948.69    948.84    948.77    948.88    948.85    948.96    949.03    949.02    949.12    949.04    949.05    949.01    949.13    949.23    949.16    949.27     949.2    949.25    949.22    949.23    949.19    949.23     949.4    949.35    949.25    949.25    949.35    949.18    949.25    949.17    949.35     949.3    949.23    948.92    948.89    948.88    948.93    948.89    948.88    948.88    948.94    949.07    948.96    948.83    948.73    948.75    948.82    948.87    948.85    948.75    948.83    948.76    948.73    948.79    948.92     948.9
    {'01/01/12-Other'  }      4.46      4.46      4.46      4.45      4.46      4.45      4.46      4.46      4.44      4.26       2.5      2.39      2.39      2.39      2.39      2.39       2.4       2.4       2.4       2.4       2.4      2.41      2.52      2.61      2.61       2.6      2.44      2.24      2.24      2.25      2.27       2.5      2.45      2.59      3.59       4.1      4.14      4.11      4.17      4.19      4.18      4.18      4.18      4.18      4.18      4.18      4.21      4.22       4.1      4.05      4.05      4.05      4.05      4.05      4.03      4.04      3.98      3.99      3.91      3.84         4      4.06      4.07      4.07      4.07      4.07      4.07      4.01       3.7      3.71      3.72      3.71      3.81       3.9       3.9       3.9      4.09      4.28      4.14      4.12      4.12      4.12      4.12      4.12      4.12      4.12      4.11      4.11      4.11      4.11      4.12      4.12      4.12      4.12      4.13      4.15
    {'01/01/12-Sun'    }         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0      0.08      0.28      0.54       0.9      1.13      1.44      1.72      1.98      2.24      2.44      2.65      2.84      2.99      3.13      3.39      3.87      3.94      3.96      4.23      4.33      4.31      4.31      4.09       3.9      3.99      3.92      3.83      3.77       3.7      3.67      3.55      3.41      3.06      2.82      2.55      2.15      1.71      1.25      0.81      0.39      0.04         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0         0
    {'01/01/12-Wind'   }    1542.6    1555.1    1512.9    1528.2    1505.3    1481.4    1504.7    1476.8    1454.5    1477.2    1438.1    1403.5    1364.7    1313.8    1284.8      1261    1237.5      1193    1167.7    1153.7    1128.5    1114.3    1118.5    1145.5    1171.2      1157    1113.9    1031.9    983.18    922.89    871.57    905.97    940.42    923.47    871.42    774.84    688.59    629.18    585.37    576.44    596.76    622.94    616.71    570.39    501.69    433.77     387.3    354.04    317.79    296.46    279.98    265.16    270.85    267.46    259.86    255.24    249.19    271.23    290.11    299.32    314.01    309.58    306.85    309.33    306.45    305.53    315.72     311.5     297.9    294.22    281.74    281.37    281.92     289.4    294.04    289.97    291.56    303.22    325.99    354.73    371.49    398.13    425.37    446.04    451.23    442.77    427.97    420.32    427.56    436.19    447.92    450.96    455.02    475.62    497.16    506.87
    {'01/02/12-Biomass'}      8.16      8.17      8.17      8.16      8.17      8.16      8.17      8.17      8.18      8.17      8.17      8.18      8.19      8.19      8.19      8.18       8.2       8.2      8.19      8.22      8.17      8.19      8.16      8.12      8.02      8.01      8.01      8.03      8.01      8.04      8.02       7.9      7.85      7.84      7.84      7.83      7.83      7.84      7.82       7.8      7.79       7.8      7.78       7.8      7.79       7.8      7.37      6.94      6.93      6.99      7.43      7.76       7.8      7.79       7.8      7.79      7.79      7.78      6.82      7.14      7.75      8.03      7.95      7.81      7.87      7.77      7.78      7.73      7.73      7.88      8.06      8.05      8.06      8.06      8.07      8.01      7.45      7.08      7.08      7.33      7.61      7.78      7.77         8      8.14      8.14      8.13      8.13      8.14      8.14      8.13      8.15      8.12      8.09      8.07      8.07
    {'01/02/12-Coal'   }    3091.6    3055.1    3028.4    3004.9    3001.6    3008.4    2996.2    2990.7      2992    3007.5    3010.9    3013.1      3029      3053      3084    3126.8    3161.9      3178    3188.4    3206.6    3236.4    3259.6    3288.2    3354.2    3350.2    3380.6    3427.1    3508.2    3594.9    3623.7    3636.3    3639.4      3624    3619.7    3634.3    3654.7    3700.3    3721.9    3710.9    3700.4    3715.1      3719    3726.2    3710.8      3697    3700.1    3654.1    3610.2    3585.3    3580.7      3531    3498.2    3438.4    3389.9    3348.9    3301.6    3250.9    3211.8      3175    3137.1    3061.4    3030.2    3011.1    3008.7    3001.4    3042.8    3063.2      3061    3117.2    3228.4    3388.7    3569.3    3683.7    3742.3    3756.7    3758.4    3766.6    3771.4    3770.8    3772.7    3776.3    3787.1    3783.8    3777.3    3755.6      3730    3696.1    3675.1    3657.9    3607.2    3548.8    3577.1    3540.4    3484.6    3356.7    3251.6
    {'01/02/12-Gas'    }    127.54    127.59    127.05    127.32    127.66    128.16    128.12    128.12    128.08    128.15    128.63    128.93    128.25    128.04    127.58    127.86    128.38    128.35    127.91    128.22    128.56    127.95    127.36    127.85    140.34    141.18    140.24    140.51    141.41    150.95    149.77    149.23    149.62    146.11    143.88    143.82    141.49    140.14    139.27    139.62     139.5    138.54    139.03    138.72    138.11    137.75    137.39    137.54     136.9    136.92    137.64    136.79    137.23    137.65    137.24    137.29    137.05     136.7    137.43    137.34    137.59     136.9    136.39    137.77    139.16    137.45    139.96    141.62    143.41    143.64    144.84    159.94    176.45    181.64    191.44    197.93    197.73       194    193.18    193.22    197.99    199.26    197.04    194.71    189.21    170.29    153.59    147.64    141.36    133.68    132.93    127.27    125.76    125.84    126.91    127.15
    {'01/02/12-Gas_CC' }    2602.7      2610    2603.2    2598.2    2592.7    2573.3    2575.6    2572.7    2587.6    2586.1    2584.8    2600.6    2626.3    2634.9    2650.7    2646.1    2681.3    2706.6    2760.9    2818.1    2949.2    3034.8      3117    3165.2    3382.3    3496.3    3579.5    3642.9    3694.8    3679.9      3663    3660.9    3687.1    3712.6    3741.1    3760.5    3781.6    3792.7    3791.2    3788.9    3795.5    3749.3    3711.9    3660.9    3649.1    3614.8    3622.3    3614.6    3658.1    3623.5    3611.2    3575.1    3543.9    3541.8    3533.4    3506.4    3485.4    3493.2    3461.2    3467.8      3408    3420.8    3418.8      3425    3419.9    3498.6      3466    3521.6    3543.7    3601.7    3725.9    3898.5    3936.5    4037.6    4053.8    4111.1    4101.9    4129.9    4143.6    4151.7      4171    4165.5    4161.2    4133.4    4083.2      4057    4026.1    3912.8      3768    3651.1    3593.1    3437.3      3457    3408.3    3352.2    3351.6
    {'01/02/12-Hydro'  }     15.44     15.15     15.15     15.15     15.11     15.02     14.51      7.35      7.35      7.35      7.36      7.35      7.34      7.34       7.3      7.32      7.33      7.33      7.32      7.31      7.43      7.43      7.43      7.45      9.48     10.49     10.49     10.52      8.81       8.4      8.41       8.4      8.45      8.47      8.47      8.45      8.44      8.44      8.45      8.48      8.47      8.45      8.47      8.48      8.49      8.47      7.84      7.62       7.4      7.34      7.38      7.36      7.32      7.33      7.31       7.8     14.76     14.79      14.8     14.79     14.83     14.79     14.81     14.79     14.83      7.52     14.17     15.05     20.02     20.86     20.88     20.89     21.02     21.02     21.16     21.05     21.12     21.16     21.27     21.15     16.26     16.29      16.2     16.15     16.24     16.24     15.99      8.51      8.46      8.46      8.45      8.48      8.45      8.44      8.47      8.47
    {'01/02/12-Nuclear'}     948.9    948.88    948.92    949.03    948.95    948.93       949    948.91    948.97    948.99    949.04    949.24    949.21    949.15    949.04    949.17    949.22    949.19    949.18    949.37    949.47    949.07    949.08    948.99    949.33    949.02     949.1    948.98    949.16    949.03    949.05    949.06    949.03    948.85    948.97    949.08    949.12    949.25    949.17    949.29    949.22    949.09    949.32     949.3    949.26     949.2     949.3     949.3    949.31    949.22    949.53    949.36    949.54    949.61     949.4    949.63    949.39    949.44    949.48    949.59    949.72    949.43    949.75    949.53    949.68     949.6    949.78    949.79    949.73    949.91    949.79     949.6    949.56    949.58    949.62    949.61    949.69    949.64    949.55    949.48    949.49    949.49    949.35    949.29    949.59    949.44    949.27    949.33    949.38    949.29    948.93     949.5    949.16    949.01    949.16    949.11
    {'01/02/12-Other'  }      3.94      3.81      3.82      3.82      3.82      3.82      3.82      3.82      3.82      3.82      3.83      3.83      3.82      3.82      3.82      3.81      3.82      3.81      3.82      3.81      3.56      3.48      3.46      3.45      3.44      3.43      3.45      3.45      3.45      3.46      3.46      3.46      3.57      3.64      3.64      3.65      3.61      3.13      3.17      3.26      3.64      3.66      3.67      3.74      3.73      3.98      3.99      3.99      3.99      3.99      3.99         4       4.1      4.17      4.17      4.17      4.04      3.99      3.99      3.99      3.99      3.99         4      3.99      3.99      3.99      3.99      3.99      3.98      3.99      3.98      3.97      3.98      3.98      3.99      3.98      3.98      3.98      3.98      3.97      4.09      4.14      3.92      3.81      3.81      3.82      3.81      3.83      3.98      3.98      3.98      3.98      3.97      3.97      3.97      3.96

P = digitsPattern+":"+digitsPattern;
U = stack(T, P, 'NewDataVariableName','Data', 'IndexVariableName','QuarterHours')

U = 26784×3 table
         Date-Fuel          QuarterHours    Data
    ____________________    ____________    ____

    {'01/01/12-Biomass'}        0:15         8.3
    {'01/01/12-Biomass'}        0:30        7.61
    {'01/01/12-Biomass'}        0:45        7.32
    {'01/01/12-Biomass'}        1:00        7.32
    {'01/01/12-Biomass'}        1:15        7.32
    {'01/01/12-Biomass'}        1:30        7.43
    {'01/01/12-Biomass'}        1:45        7.83
    {'01/01/12-Biomass'}        2:00        7.98
    {'01/01/12-Biomass'}        2:15        8.19
    {'01/01/12-Biomass'}        2:30        7.97
    {'01/01/12-Biomass'}        2:45        7.31
    {'01/01/12-Biomass'}        3:00        7.63
    {'01/01/12-Biomass'}        3:15        7.94
    {'01/01/12-Biomass'}        3:30        8.04
    {'01/01/12-Biomass'}        3:45        8.23
    {'01/01/12-Biomass'}        4:00        8.13

C = split(U.('Date-Fuel'),'-');
D = strcat(C(:,1),'_',cellstr(U.QuarterHours));
U.Fuel =   C(:,2);
U.Date = datetime(D,'InputFormat','d/M/yy_HH:mm', 'Format','yyyy-MM-dd HH:mm')

U = 26784×5 table
         Date-Fuel          QuarterHours    Data       Fuel              Date      
    ____________________    ____________    ____    ___________    ________________

    {'01/01/12-Biomass'}        0:15         8.3    {'Biomass'}    2012-01-01 00:15
    {'01/01/12-Biomass'}        0:30        7.61    {'Biomass'}    2012-01-01 00:30
    {'01/01/12-Biomass'}        0:45        7.32    {'Biomass'}    2012-01-01 00:45
    {'01/01/12-Biomass'}        1:00        7.32    {'Biomass'}    2012-01-01 01:00
    {'01/01/12-Biomass'}        1:15        7.32    {'Biomass'}    2012-01-01 01:15
    {'01/01/12-Biomass'}        1:30        7.43    {'Biomass'}    2012-01-01 01:30
    {'01/01/12-Biomass'}        1:45        7.83    {'Biomass'}    2012-01-01 01:45
    {'01/01/12-Biomass'}        2:00        7.98    {'Biomass'}    2012-01-01 02:00
    {'01/01/12-Biomass'}        2:15        8.19    {'Biomass'}    2012-01-01 02:15
    {'01/01/12-Biomass'}        2:30        7.97    {'Biomass'}    2012-01-01 02:30
    {'01/01/12-Biomass'}        2:45        7.31    {'Biomass'}    2012-01-01 02:45
    {'01/01/12-Biomass'}        3:00        7.63    {'Biomass'}    2012-01-01 03:00
    {'01/01/12-Biomass'}        3:15        7.94    {'Biomass'}    2012-01-01 03:15
    {'01/01/12-Biomass'}        3:30        8.04    {'Biomass'}    2012-01-01 03:30
    {'01/01/12-Biomass'}        3:45        8.23    {'Biomass'}    2012-01-01 03:45
    {'01/01/12-Biomass'}        4:00        8.13    {'Biomass'}    2012-01-01 04:00

V = unstack(U,'Data','Fuel', 'GroupingVariables','Date')

V = 1152×10 table
          Date          Biomass     Coal      Gas      Gas_CC    Hydro    Nuclear    Other    Sun     Wind 
    ________________    _______    ______    ______    ______    _____    _______    _____    ___    ______

    2012-01-01 00:15      8.3      2516.7    113.68    1488.8    7.67     948.15     4.46      0     1542.6
    2012-01-01 00:30     7.61      2484.7    112.89    1489.7    7.37     948.48     4.46      0     1555.1
    2012-01-01 00:45     7.32      2482.2    115.51    1511.4    7.38     948.29     4.46      0     1512.9
    2012-01-01 01:00     7.32      2469.9    114.61    1486.9    7.37     948.51     4.45      0     1528.2
    2012-01-01 01:15     7.32      2448.7    114.45    1478.4    7.35     948.55     4.46      0     1505.3
    2012-01-01 01:30     7.43      2441.7    114.15      1468    7.34     948.45     4.45      0     1481.4
    2012-01-01 01:45     7.83      2399.4    112.18    1447.4    7.34      948.3     4.46      0     1504.7
    2012-01-01 02:00     7.98        2362    112.38    1475.1    7.35     948.41     4.46      0     1476.8
    2012-01-01 02:15     8.19      2348.3    111.97    1468.6    7.34     948.19     4.44      0     1454.5
    2012-01-01 02:30     7.97      2281.9    112.09    1467.2    7.34     948.16     4.26      0     1477.2
    2012-01-01 02:45     7.31      2267.7    111.97    1464.5    7.35     948.24      2.5      0     1438.1
    2012-01-01 03:00     7.63      2260.9    112.01    1489.3    7.34     948.25     2.39      0     1403.5
    2012-01-01 03:15     7.94      2303.9    113.25    1528.5    7.33     948.18     2.39      0     1364.7
    2012-01-01 03:30     8.04      2364.2    115.19    1507.1    7.33     948.15     2.39      0     1313.8
    2012-01-01 03:45     8.23      2391.6     114.8    1498.4    7.32     948.23     2.39      0     1284.8
    2012-01-01 04:00     8.13      2418.5    113.99    1486.8    7.32     947.98     2.39      0       1261

Having your data arranged this way will make it much easier to work with. For example:

format compact
summary(V)

Variables:
    Date: 1152×1 datetime
        Values:
            Min       2012-01-01 00:00
            Median    2012-06-16 11:52
            Max       2012-12-01 23:45
    Biomass: 1152×1 double
        Values:
            Min         4.82  
            Median     8.035  
            Max        12.77  
    Coal: 1152×1 double
        Values:
            Min        2096.2 
            Median     2960.2 
            Max        3824.8 
    Gas: 1152×1 double
        Values:
            Min        111.27 
            Median     149.76 
            Max        602.92 
    Gas_CC: 1152×1 double
        Values:
            Min        1447.4 
            Median     3269.1 
            Max        5354.2 
    Hydro: 1152×1 double
        Values:
            Min         6.89  
            Median      8.11  
            Max        30.04  
    Nuclear: 1152×1 double
        Values:
            Min        906.21 
            Median     948.55 
            Max        951.15 
    Other: 1152×1 double
        Values:
            Min         1.29  
            Median      4.11  
            Max         5.29  
    Sun: 1152×1 double
        Values:
            Min            0  
            Median         0  
            Max         8.44  
    Wind: 1152×1 double
        Values:
            Min          8.82 
            Median     900.15 
            Max        1746.1