I have a Matlab script with an output of a multidimensional array LCOE (3 dimensions) of size 16:12:34. This output needs to be written to Excel, therefore I use xlswrite.
I have tried this:
T = LCOE(:,:,1);
xlswrite('filename', T, 'sheetname', 'B2');
This does what it's supposed to, but only writes one table to excel, and I would like to write all 34 tables to excel underneath each other, spaced by `2 blank rows.
Then, I tried this:
for y = 1:34
T = LCOE(:,:,y)
xlswrite('filename', T, 'sheetname', strcat('B', num2str(2+(y-1)*18)));
This works, but is very slow, since matlab writes each table separately to excel. Is there a faster way to do this?
Instead of using xlswrite again and again. Dump all the values of a 3D matrix into a 2D matrix and add rows of NaNs so that when you write that to excel file, you get 2 blank rows.
Following code improves the execution time by the factor of more than 10.
LCOE = 100*rand(16,12,34); % Taking random values for LCOE
T = NaN(18*34-2 ,12); % 1. Pre-allocation 2. 16+2 = 18
% Following loop dumps all the values of 3D matrix into a 2-D followed by 2 rows of NaN
% to leave 2 blank rows in excel file.
for k = 1:34
T(18*(k-1)+[1:16], :) = LCOE(:,:,k);
end
xlswrite('filename', T, 'sheetname', 'B2'); % Writing the Excel file
In my system, my code takes about 1 second to execute while your code takes about 10.5 seconds. So that's a significant difference.
Related
I know how to read in multiple Excel files, but am struggling to conduct the same analysis on all of those files. The analysis requires I average some values in different columns, then print those average values to a separate Excel sheet. I can do this with one Excel file, but have trouble figuring out how to print each average value in a different row in the output Excel file. Here is the code I have that works for one file (reads it, averages values in column 4, then prints to a separate Excel file):
data = xlsread('test_1.xlsx');
average_values_1 = data(:,4);
a = [average_values_1];
data_cells = num2cell(a);
column_header ={'Average Value 1'};
row_header(1,1) ={'File 1'}
output = [{' '} column_header; row_header data_cells];
xlswrite('Test Averages.xls', output);
How might I do this over and over again while printing values from each file in the output file as its own table? I suspect a nested loop is in my future.
Thanks in advance.
Here is working example of what you possibly want to do with xlswrite[1]:
filename = 'testdata.xlsx'; % Filename to save average values in
for k = 1:10 % Looping for 10 iterations
sheet = 2; % Selecting sheet2
Avg = randi([1 10],1,1); % Generating a random average each time the loop is run
xlRange = char(64+k); % 65 is the ASCII value of A
xlswrite(filename,Avg,sheet,xlRange); % Writing the excel file
end
This code gives the following output [2] :
Fig.1: Values are saved in a single row of excel file
If you want to get the output in a single column then use this xlRange = ['A',num2str(k)]; instead. It'll give you the following output [2] :
Fig.2: Values are saved in a single column of excel file
[1]: Read the documentation of xlswrite for more details.
[2]: Output values may vary since random integers are generated.
The following matlab code writes 4 columns [2x1] in an excel sheet side by side, making a [4x4] matrix.
y = zeros(2,4); % I must make a zero matrix before I fill it
for i = 1:4 % 4 iterations for 4 columns
y(:,i) = rand(2,1); % saving the columns in the 'y' matrix
xlswrite('Book2.xlsx',y,'A1') % writing the columns one by one in the excel sheet
end Its ok over here. But I would like to write 2 [2x2] matrices side by side. Then I change the code,
y = zeros(2,4);
for i = 1:2 % two iterations instead of 4
y(:,i) = rand(2,2); % now I have 2 [4x4] matrices instead of 4 [2x1] columns
xlswrite('Book2.xlsx',y,'A1')
end
Unfortunately I get the following error:
Assignment has more non-singleton rhs dimensions than non-singleton subscripts
How can I succeed to my target by overcoming the error?
Is there any idea?
Thank you in advance
I have a script that does the following: I have an Excel spreadsheet with three columns of Chlorophyll concentrations and sometimes more. Eg. 1) WholeFluro 2) WholeHPLC 3) Net1Fluro but not all three columns have all 3 datasets. For instance, I often have WholeFluro and WholeHPLC OR just Net1Fluro. In order to have more data I like to merge all the data into one data column. In addition I also have the corresponding locations in the ocean where I collected the data from as well as the depths in the water column from where my sample was draw.
I have a MATLAB script that I use for this but it’s very long and it takes me long to use it for different types of data that I want to merge. I was wondering if I could get some help to make it more efficient as it would also help me learn to write better scripts.
My script is as follows:
% go to the data folder
cd C:\Users\Documents\CHLOROPHYLL_DATA_PROCESSED\
filename = 'Knorr-Working_SizeFracNew.xlsx';
[num,txt,raw] = xlsread(filename);
% Pick out the relevant data that you need from the large spreadsheet
%Use Raw only to get header info because I can see the header info that I %cannot see in ‘num’
% Use ‘num’ to get actual data
FracsData=num(:,[1:2:7 8:2:17 19:23 24 29 34]);
FracsHeaderInfo=raw(:,[1:2:7 8:2:17 19:23 24 29 34]);
%%
% choose the various Chlorophyll data from the large spreadsheet that I want %to merge
% Here I want to Merge the two columns which have Whole, two columns with
% Net1, two columns with % Net2 and two columns with Net3
WholeFluro=FracsData(:,6);
WholeHPLC=FracsData(:,10);
Net1Fluro=FracsData(:,7);
Net1HPLC=FracsData(:,15);
Net2Fluro=FracsData(:,8);
Net2HPLC=FracsData(:,16);
Net3Fluro=FracsData(:,9);
Net3HPLC=FracsData(:,17);
%%
%Replace NaNs with -999 or I get an error when NaNs from various columns %clash
WholeFluro(isnan(WholeFluro))=-999;
WholeHPLC(isnan(WholeHPLC))=-999;
Net1Fluro(isnan(Net1Fluro))=-999;
Net1HPLC(isnan(Net1HPLC))=-999;
Net2Fluro(isnan(Net2Fluro))=-999;
Net2HPLC(isnan(Net2HPLC))=-999;
Net3Fluro(isnan(Net3Fluro))=-999;
Net3HPLC(isnan(Net3HPLC))=-999;
% Here I create 4 variables that will hold my merged data for whole, N1, N2, % & N3 that are equal to the % the original data
MergedDataWhole = WholeFluro;
MergedDataN1 = Net1Fluro;
MergedDataN2 = Net2Fluro;
MergedDataN3 = Net3Fluro;
%find the empty places and fill them up with the HPLC data at points x – I %give HPLC data precedence
x=find(MergedDataWhole==-999);
MergedDataWhole(x)=WholeHPLC(x);
x=find(MergedDataN1==-999);
MergedDataN1(x)=Net1HPLC(x);
x=find(MergedDataN2==-999);
MergedDataN2(x)=Net2HPLC(x);
x=find(MergedDataN3==-999);
MergedDataN3(x)=Net3HPLC(x);
MergedDataALL=horzcat(MergedDataWhole,MergedDataN1,MergedDataN2,MergedDataN3);
MergedDataALL(MergedDataFracs<0)=0;
outputfilename = 'Merged.xlsx';
[suc,msg] = xlswrite(outputfilename,Merged);
I have a .mat file which contains titles={'time','data'} and 2 column vectors:
time=[1;2;3;4;5] and data=[10;20;30;40;50].
I created a new cell called table={'time','data';time data} and i used:
xlswrite(filename,table);
However, when i open the xlsx file it shows me only the titles and not showing the numbers.
I saw that xlswrite will show empty cell in case im trying to export more than 1 number in a cell.
Is there anything i can do to export the whole vector instead of writing each value in it's cell?
The final result that i tried to get is like this:
time data
1 10
2 20
3 30
4 40
5 50
You have a couple options. Usually what I do is break it into two xlswrite calls, one for the header and one for the data.
titles = {'time','data'};
time = [1;2;3;4;5];
data = [10;20;30;40;50];
xlswrite('myfile.xlsx', titles, 'Sheet1', 'A1');
xlswrite('myfile.xlsx', [time, data], 'Sheet1', 'A2');
Alternatively, if you have R2013b or newer you can also use the table builtin, which has its own method for writing out data. With the same sample data:
mytable = table(time, data, 'VariableNames', titles);
writetable(mytable, 'myfile.xlsx');
I have a looping data matrix in matlab, and I want to write it into same excel file. If I use the xlswrite('name.xls', M) it'll make a 'name.xls' excel, contained one matrix (value of the last looping). How can I write all my looping matrix (lets say it has 10 matrix with 13 columns) in one file excel and that excel file will contain all my matrix with 13 columns (so there'll be 10 rows with 13 columns). Please help, Thanks. -Machmum
In each loop iteration add your newest vector to a single matrix. Then only after the loop, write this matrix to a .xls file:
M = zeros(10,13); %// Pre-allocation like this is essential for speed
for k = 1:10
... %Your code
M(k,:) = ... %//Put your new 1-by-13 vector that you create each iteration here
end
xlswrite(file_name, M)
Although it would be better to create the matrix first and then write it in one go as Dan has suggested, it is possible to specify where xlswrite starts writing, which allows you to append data to existing files. If only specifying a start location, you must also give xlswrite a sheet name. This will be slower than pre-calculating the matrix and then just calling xlswrite once, though.
Simple example:
M = 1:10;
for n = 1:10
t = sprintf('A%d',n); % starting cell A1 through A10
xlswrite('testdata.xls',M*n,'Sheet1',t); % writes one row
end