Matlab: Reading in data from an excel spreadsheet as a single integer

I am reading in data from an excel spreadsheet, but I am unable to use a comparison on what I read in. How can I read in a cell from an excel spreadsheet and compare what I get to a number? I'm pretty sure anything read from a spreadsheet is made into an array Here is the relevant code (edit: I'll give the whole code of what I have; edit2: Minor fixes, but being so new to MatLab, I think I'm not familiar with how to declare a variable):

>> for k = 2:4997
      colF = 'F';
      colE = 'E';
      row = int2str(k);
      entryF = strcat(colF, row);
      entryE = strcat(colE,row);

        millisecond = xlsread('someFile.xlsx', 1, entryE);
        [~,message] = xlsread('someFile.xlsx', 1, entryF);

        if millisecond == 1
           soundMoment = 0;   
        elseif strcmp(message, 'probe_sound')
           soundMoment = millisecond;
        end

        if soundMoment == 0
           xlswrite('someFile.xlsx', 'preprobe', 1, entryF);
        elseif millisecond > soundMoment
           xlswrite('someFile.xlsx', 'postprobe', 1, entryF);
        end

     end

[Walter Roberson]

Please check your file names: probably you should not have the * in the first one.

You should be using strcmp(message, 'probe_sound') instead of using == to compare the strings.

[Aldin]

You say entryE is number an entryF is text than you can in my opinion make this compare:

if entryE = 1

soundMoment = 0;

elseif strcmp(entryF,'probe_sound')

soundMoment = millisecond;

end

[Aldin]

The star and backslash is not needed. just type xlsread('someFile.xlsx',1,entryE)

[Walter Roberson]

EntryE and EntryF are locations in the file, not the entries themselves.

The "=" operator cannot be used in an "if" statement; "==" is the comparison operator.

[Aldin]

"good eye" :)

read data in excel and than xlswrtie the same data and than compare

what you want

[Louis]

The error I get in MatLAB is:

Error using == , Matrix dimensions must agree.

So I know the problem is with what I read in, the only issue is WHAT the datatype is of millisecond and message. Do I just need to convert message into a string, and millisecond into an integer?

[Aldin]

1 is an number you have to convert millisecond to number "str2num"

also for soundMoment

[Louis]

So anything read in from excel is a string?

[Aldin]

NO

if you type the code below your variable "name" is string

[Louis]

I don't follow. Does the ~ in [~,name] stand for something? And name is just what I want my variable to be named?

[Aldin]

It is your variable . In your case : "message" see bellow

[Louis]

No error with the [~,message] bit, but now it says: Error using str2num (line 33), Requires string or character array input.

[Walter Roberson]

In 2009b onward, a ~ on the left-hand side of an assignment means to throw away the corresponding output argument. If you are using a version before 2009b, replace the ~ with any variable name that is not being used.

[Aldin]

delete all str2num functions in your code. And what is preprobe and postprobe it is the data to read in file???

[Aldin]

and declare soundMoment before if statement!!!!

[Aldin]

and put so in your code 'preprobe' and 'postprobe' And than it works

by me :)

[Louis]

Oops, preprobe and postprobe are supposed to be strings that I'm writing into that spot in the Excel spreadsheet. I thought in MatLAB that declarations weren't needed.

[Aldin]

What's going now with your code :)

[Louis]

Did another small edit to the code, but I'm assuming to declare soundMoment, int soundMoment should work?

[Walter Roberson]

Declarations are not required. The problem is that your conditions do not specify what soundMoment should be set to if neither test is met.

[Louis]

I did "else soundMoment = -1;" and now there are no errors. The excel spreadsheet is quite big, so I'll have to wait to see if it came out as intended.

[Louis]

It works, except it's never listing anything as preprobe. I get all postprobe right, but preprobe isn't showing.

[Louis]

It works as intended, I made a small error in the file name.

[Aldin]

In MATLAB there is no declaration such as in JAVA we have int, float, double, string...

[Aldin]

Did that do what you want? If so, mark it as "solved."

Answer 1

[Aldin]

Here is the right code for getting data from excel doc.

[~,name] = xlsread('test.xlsx',1,'A1')

Answer 2

[Aldin]

Edit your code with this:

[~,message] = xlsread('someFile.xlsx', 1, entryF);

your code seems to be OK