MATLAB: How to fix ‘Undefined function or variable ‘temp’ in ode45′.

functionode45undefinedvariable

My code below gives me the error

Undefined function or variable 'temp'.

when using the command

   [t,u] = ode45(@temp,[0,20],[20]);

which I intent to create a graph with. As a note, I used 'global' to define and then set the values of my constants.

If necessary, the purpose of this code is to create a graph for a CPU temperature based on data from a lab.

Best Answer

Where is the file temp.m located? Is it in the current directory or on the MATLAB path? Is it a sub-function? The error indicates MATLAB does not see the file temp.m from where you call ode45.

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MATLAB: How to solve this issue ((((Undefined function ‘m_shaperead’ for input arguments of type ‘char’))))

Reyadh - given the error message, it sounds like you no longer have this file or it isn't within the MATLAB search path. In the Command Window, type

 which m_shaperead -all

to see if this file/function can be found. If you observe the

 'm_shaperead' not found.

then either download the mapping package again and save its folder to the MATLAB search path, or if you are sure that you already have the file, then add this folder to the search path.

MATLAB: Is MATLAB 7.0.4 (R14SP2) unable to recognize the files, when I use the COPYFILE command in the script

This bug has been fixed in Release 14 Service Pack 3 (R14SP3). For previous product releases, read below for any possible workarounds:

This has been verified as a bug in MATLAB 7.0.4(R14SP2) in the way COPYFILE notifies MATLAB about the changes made to a destination directory.

The followings are some workarounds to resolve the issue:

1. Using an absolute path name:

Use an absolute path name as an input to functions(TYPE in this case) accessing the destination directory as follows:

FullPathTempDir = tempname; 
[temp_dir temp_file] = fileparts(FullPathTempDir); 
mkdir(FullPathTempDir); 
destinationFile = [temp_file,'.m']; 
origPath = addpath(FullPathTempDir); 
copyfile('hSampleDisp.m',fullfile(FullPathTempDir,destinationFile)); 
type(fullfile(FullPathTempDir,destinationFile));

2. Use WHICH or EXIST on the path of the destination directory as follows:

FullPathTempDir = tempname; 
[temp_dir temp_file] = fileparts(FullPathTempDir); 
mkdir(FullPathTempDir); 
destinationFile = [temp_file,'.m']; 
origPath = addpath(FullPathTempDir); 
copyfile('hSampleDisp.m',fullfile(FullPathTempDir,destinationFile)); 
which temp_file
type(temp_file);

3. CD to the directory, in which the file is located, before accessing the file.

Best Answer

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MATLAB: How to solve this issue ((((Undefined function ‘m_shaperead’ for input arguments of type ‘char’))))

MATLAB: Is MATLAB 7.0.4 (R14SP2) unable to recognize the files, when I use the COPYFILE command in the script

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