xlsread unable to import data or sorts the imported data. please advice.

Question

nitin arora 2015-4-17

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https://ww2.mathworks.cn/matlabcentral/answers/204010-xlsread-unable-to-import-data-or-sorts-the-imported-data-please-advice

编辑： nitin arora 2015-4-27

采纳的回答： Ken Atwell

I am trying to read x and y coordinates into separate arrays, say x and y. Sometimes,

xlsread does not read any value from the specified column
xlsread grabs the value from the column but sorts them resulting in mismatch between x and y coordinates

I am not sure whats the way around? Is it a bug? It happens sometimes only.

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Image Analyst 2015-4-17

编辑：Image Analyst 2015-4-17

It could be a weird entry in your Excel cell. Who knows? Not us, because you didn't attach a workbook for which it fails for us to check.

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Answer 1

Ken Atwell 2015-4-18

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在 MATLAB Online 中打开

Nitin, I was able to load this 20 times in a row without issue. But, I am on Mac, which uses quite a different code path than a Windows computer (you didn't say what OS you are using), so we may not be making much of a comparison.

Try not to have Excel running on your computer at the same time you run this code. I've heard claims, but never personally verified, that reliability drops when Excel is being used both as a Desktop application and Automation server.

This is a stab in the dark, but try loading the spreadsheet in one command, passing 'basic' as the fourth argument to xlsread. This will cause MATLAB to read the file with its own reader, instead of bridging to Excel using Automation to do the read. The assign the columns to individual variable. Maybe there is some kind of timing issue with running xlsread in rapid succession? That code would look like:

 foo=xlsread('test1.xlsx','Sheet1','','basic');
 ya=foo(:,1);
 za=foo(:,2);
 yb=foo(:,28);
 zb=foo(:,29);

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nitin arora 2015-4-27

编辑：nitin arora 2015-4-27

Thanks Ken, I did not get into the problem of xlsread sorting my data again. you are right that excel was open when I was trying to import the data from excel into matlab.

Thanks image analyst.

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Answer 2

Ken Atwell 2015-4-17

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https://ww2.mathworks.cn/matlabcentral/answers/204010-xlsread-unable-to-import-data-or-sorts-the-imported-data-please-advice#answer_175552

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I can answer question #2, I think. If you have two separate variables and you sort one, then, yes, the two variables will now be out of sync. To can overcome this by:

Use a container like a table that keeps columns of related data synched.
Use the second output of sort and apply that to the second array:

 [X, I] = sort(X);
 Y = Y(I);

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Image Analyst 2015-4-17

Please attach test.xlsx. You probably just clicked the "Choose file" button but forgot to click the "Attach file" button. And just to be clear, you're saying that it is the xlsread() itself that is rearranging/sorting the cells and you are definitely not calling sort() yourself, right?

nitin arora 2015-4-17

编辑：nitin arora 2015-4-17

在 MATLAB Online 中打开

test1.xlsx

Sorry. Please find ignore the previous message and code. Yes, xlsread() sorted my data yesterday without using any sort command. Attached code is not sorting the data today but it was doing that yesterday. After restarting the desktop, the problem went away.

If I saw this sorting behavior again, I will let you know.However, attached code is unable to pick some columns. Please run the code several times. Sometimes, the value gets picked but sometimes it does not. Seems like a bug.

 clc
clear all

ya = xlsread('test1.xlsx','Sheet1','A3:A7'); za = xlsread('test1.xlsx','Sheet1','B3:B7'); yb = xlsread('test1.xlsx','Sheet1','AB3:AB7'); zb = xlsread('test1.xlsx','Sheet1','AC3:AC7');

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