Check If Some Fields Exist On Mat File

If you use isfile to check whether a directory exists the method will return false here s an example of isfile being used to check if a.

Check if some fields exist on mat file.

If i run exist mandrill file i get false back which i normally would interpret as the mat file doesn t exist in the matlab search path. Load myfiles i name myvar if exist myvar var disp myvar num2str myvar. For very large files the best practice is to read and write as much data into memory as possible at a time. If name matches both a variable and a p code file exists returns 1 identifying it as a variable.

The isfile method only works for files. The isfile function searches for files only on the specified path or in the current folder. However imgdata load mandrill works perfectly fine. Check for existence of mat file in search path.

Display the value of myvar. If isfile filename file exists. If our file path exists our code will return the python boolean value true. Myfiles dir mat.

For example you can save data to a subset of a variable in a mat file or read a subset of a variable into the matlab workspace. Exampleobject b 1 firstrowb. Firstrowb exampleobject b 1. Open the matlab editor and paste the following function into it.

If name matches both a folder and a matlab function exist returns 7 identifying it as a folder. Save data to a subset of a variable y in the file myfile2 mat using the mat file object. To determine if a field exists at any level in a nested structure create a new function that examines all levels of the structure. Here is a simple example to read all the mat files in a given directory and load a variable named myvar if it exists.

Just came over an interesting problem. It does not work for directories. For i 1 length myfiles clear myvar. Firstrowb 2 firstrowb.

For r2017a and previous releases use the exist function. Update the values in the first row of variable b in example mat using the values stored in firstrowb. Exist searches for files and folders on the search path which can lead to unexpected results. Access specific parts of a variable in a mat file using the mat file object.

To check the existence of a file or folder you also can use the isfolder or isfile functions. Same applies for the seamount image or any other images that come along with matlab toolboxes. If there is no existing file and therefore no existing file path our code will return false. For example if name matches both a file with a m extension and a p code file then exist returns 6 identifying it as a p code file.

First create the mat file object m. File does not exist.