Run this code for every certain columns of tables in a cell and saving the result in new cell
조회 수: 1 (최근 30일)
이전 댓글 표시
Hi all,
I have a cell named C. In the C I have 71 tables. Each table has a column named rrr24. I want to run this code below for each rrr24 in the tables and save the results in another cell named C_new.
Here this code which in the first line just uses the first table in the C.
I want the name of each table at the new cell (C_new) to be the name of each table highlighted in the station_name column of each table. Or copy station_name column from each table and paste it as a first column of the same table in the C_new.
I attached C.
Thank you
td = C{1, 1}.rrr24; % example for C{1, 1}
n=length(td);
sc_set= [3,6,12,24];
SI=zeros(n,length(sc_set));
for q = 1:length(sc_set)
sc = sc_set(k);
if length(td(td>=0))/length(td)~=1
SI(n,q)=nan;
else
SI(1:sc-1,q)=nan;
A1=[];
for i=1:sc,
A1=[A1,td(i:length(td)-sc+i)];
end
Y=sum(A1,2);
nn=length(Y);
SI1=zeros(nn,1);
for k=1:12
d=Y(k:12:nn);
nnn=length(d);
bp=zeros(nnn,1);
for i=1:nnn
bp(i,1)=sum(d(:,1)<=d(i,1));
end
y=(bp-0.44)./(nnn+0.12);
SI1(k:12:nn,1)=y;
end
SI1(:,1)=norminv(SI1(:,1));
%output
SI(sc:end,q)=SI1;
end
end
댓글 수: 2
Guillaume
2020년 2월 5일
I'm sure I've answered a question of yours before, where I advised that having several tables is not a good idea. Most likely, it would be simpler to do whatever you want if you all your data in just one table.
Indeed, here it is: Counting all NaNs..., where the 1st thing I did is merge back all these tables to make the processing much easier.
With regards to the code you've posted above, I'm sorry it's unreadable. Good code should have comments and variable names than describe the content of the variable.
채택된 답변
fred ssemwogerere
2020년 2월 5일
Hello, I have taken a look at your workspace variable ("C"), and i think you should consider writing that program as a function file, so that you can use it for all tables in the cell array. You can use the code below and save it as your function file in the working (current) folder.
function SI = myfunction(Cn,rnum,colnum,tcol) % save this as a functionfile with filename: "myfunction.m"
%Summary of "myfunction"
% SI = output
% Cn = Cell array storing all tables
% rnum = row index of table in cell array
% colnum = column index of table in cell array
% tcol = column number of table variable ("rrr24") on which you are doing the computations
td = table2array(Cn{rnum, colnum}(:,tcol)); % example for C{1, 1}
n=numel(td);
sc_set= [3,6,12,24];
SI=zeros(n,length(sc_set));
for q = 1:length(sc_set)
sc = sc_set(q); % I have replaced "k" with "q" on this line
if numel(td(td>=0))/numel(td)~=1
SI(n,q)=nan;
else
SI(1:sc-1,q)=nan;
A1=[];
for i=1:sc
A1=[A1,td(i:numel(td)-sc+i)]; %#ok<AGROW>
end
Y=sum(A1,2);
nn=numel(Y);
SI1=zeros(nn,1);
for k=1:12
d=Y(k:12:nn);
nnn=numel(d);
bp=zeros(nnn,1);
for i=1:nnn
bp(i,1)=sum(d(:,1)<=d(i,1));
end
y=(bp-0.44)./(nnn+0.12);
SI1(k:12:nn,1)=y;
end
SI1(:,1)=norminv(SI1(:,1));
%output
SI(sc:end,q)=SI1;
end
end
end
After that, consider using the code below. It should do nicely:
Cnew=cell(1,size(C,2)); % pre-allocating your new array
for r=1:size(C,1)
for m=1:size(C,2)
SI{r,m}= myfunction(C,r,m,11);% On this line, "11" is the column index of "rrr24" (your table variable)
Cnew{r,m}=cell2table(C{r,m}.station_name); % input names under the "station_name" variable of your old tables into the new cell array based on their indexed locations
Cnew{r,m}.Output=SI{r,m}; % Add column variable, "Output" holding computed values to each table in the new cell array based on their indexed positions
Cnew{r,m}.Properties.VariableNames{1}='Station Name'; % variable name for first column of each table
end
end
댓글 수: 3
fred ssemwogerere
2020년 2월 5일
Hello, something like this for example, should do nicely;
varNames={'Station_Name','SPI_3month','SPI_6month','SPI_12month','SPI_24month'};
for k=1:size(Cnew,1)
for y=1:size(Cnew,2)
CEdit{k,y} =[(Cnew{k,y}.Station_Name),array2table(Cnew{k,y}.Output)]; %#ok<*SAGROW>
CEdit{k,y}.Properties.VariableNames=varNames;
end
end
추가 답변 (1개)
Guillaume
2020년 2월 5일
Whatever the calculation is, yes it can be done with groupsummary. As Fred wrote, you will first have to write a function to perform that calculation. However, this function should take as input: the precipitation for a station and that index scale, something like:
function spi = NonParametricStandardPrecipitationIndex(precip, indexscale)
%???
end
Then it's a straighforward groupsummary
results = groupsummary(bigtable, 'GroupingVariables', 'station_name', ...
{@(p) NonParametricStandardPrecipitationIndex(p, 1), ...
@(p) NonParametricStandardPrecipitationIndex(p, 3), ...
..etc}, 'rrr24');
Or you can make it neater by building the list of processing function for your desired scale indices beforehand:
npspi = arrayfun(@(sc) @(p) NonParametricStandardPrecipitationIndex(p, sc), [1 3 6 12 24 48], 'UniformOutput', false);
results = groupsummary(bigtable, 'GroupingVariables', 'station_name', npspi, 'rrr24');
Now with regards to the code for that function, first are you sure that the code in that fileexchange entry does what it's supposed to? Having looked at it a bit, it's very badly written! For example I was puzzling over
if length(td(td>=0))/length(td)~=1
which is simply
if any(td < 0)
why such a convoluted expression? Why write if A/B ~= 1 when if A ~= B is a lot clearer. Why calculate length(A(A>=0)) when sum(A>=0) does the same faster?
You may find that starting from scratch may be more efficient than adapting poorly written code.
참고 항목
카테고리
Help Center 및 File Exchange에서 Shifting and Sorting Matrices에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!