Convert 3 dimensional matrix to vector (rows to columns)

Hi I have a 3 dimensional matrix that I am trying to convert the rows to columns and then stack all the columns to generate a vector that will have the three dimensions. I am struggling with the coding of this

So far I have

    PV_power_output(:,:,K) = real((Vmpp_(:,:,K).*Impp_(:,:,K))*inverter_efficiency)/1000; % Power output in kW

    PV_energy(:,:,K) = sum(sum(PV_power_output(:,:,K))) ; % Energy output in kWh
PV_rows_to_columns(:,:,K) = PV_power_output(:,:,K)';

PV_power_output is a 365x24x3 matrix and I am trying to convert it to a 8760x1x3 vector

Thanks

Answer 1

[Thomas]

 doc reshape

 out = reshape(PV_power_output,8760,1,3);

Warning: read the reshape help document thoroughly as it does columnwise reshape..

[Andrew Alkiviades]

this does not seem to convert the row into a column and then stack column 2 under column1, column 3 under column 2 etc to get one column

[Thomas]

so u want row1 as column, then row2 into column under it and so on ?

[Andrew Alkiviades]

yes row 1 as column, row 2 as column and then, the new column 2 under column 1

[Thomas]

try

reshape(permute(PV_power_output,[2 1 3]),8760,1,3)

[Andrew Alkiviades]

can this be written in terms of K (since I will be adding more dimensions later on as:

out = reshape(permute(PV_power_output,[2 1 K]),8760,1,K);

[Thomas]

for reshape the product of dimension should be equal i.e. 365x24x3 == 8760x1xk (so k=3)

[Walter Roberson]

The second argument to permute() should list all of the dimension numbers. You could use

permdims = 1 : ndims(PV_power_output);

permdims(1:2) = permdims(2:1);

out = reshape(permute(PV_power_output, permdims),8760,1,[]);

[Walter Roberson]

Are you adding more dimensions, or making the third dimension larger?

[Andrew Alkiviades]

no I am to add more dimensions later (or at least have the flexibility to add/remove dimensions) of the same size

[Andrew Alkiviades]

I get an error on the perm dims(1:2) line of

"Improper assignment with rectangular empty matrix"

Cant I just transpose the matrix (for each dimension) and then vectorize it using the colon (:) somehow?

[Andrew Alkiviades]

What does the (1:2) represent?

[Walter Roberson]

Sorry should be

permdims([1 2]) = permdims([2 1]);

These are indices into permdims, which in turn is 1 to the dimension number, so the result is to get

[2 1 3 4 5 6 .... dimension number]

Answer 2

[Andrew Alkiviades]

I have managed to get it working for K = 1

I have transposed the matrix then stacked the columns. However, I need to code for the three sets of matrices - at the moment I can only access K = 1 Does anyone have any ideas on how to modify the code for the K = 2 and 3?

   PV_power_output(:,:,K) = real((Vmpp_(:,:,K).*Impp_(:,:,K))*inverter_efficiency)/1000; % Power output in kW

   PV_energy(:,:,K) = sum(sum(PV_power_output(:,:,K))) ; % Energy output in kWh

   PV_out(:,:,K) = [real((Vmpp_(:,:,K).*Impp_(:,:,K))*inverter_efficiency)/1000]'; % Power output in kW

    out = PV_out(:);