Matlab user input variable name

In summary, the user is trying to create a program where they can input the names of two previously created vectors and have the computer subtract them, generating a variable in the workspace. They are looking for a way for the user to choose the name of this variable. They have used the eval function to evaluate text strings, which can be helpful for generating variables on the fly.
  • #1
anon0219
1
0
Hi,

I am writing a program where I have the user input the name of two previously created vectors, the computer subtracts them and then generates a variable in the workspace. I was wondering if there was a way to let the user pick this name. I have so far (Y and N have been previously defined as 1 and 0):

subtract_data=input('Would you like to subtract any data sets? Y/N');
if subtract_data == 1
higher=input('Enter the name of the spectrum you would like to subtract from');
lower=input('Enter the name of the spectrum you are subtracting');
new_data=higher-lower;
filename=input('Input file name: ', 's');

...?

end

I am not sure where to go from here how to get the variable new_data to be titled what the user inputs as filename.

thanks
 
Physics news on Phys.org
  • #2
anon0219 said:
Hi,

I am writing a program where I have the user input the name of two previously created vectors, the computer subtracts them and then generates a variable in the workspace. I was wondering if there was a way to let the user pick this name. I have so far (Y and N have been previously defined as 1 and 0):

subtract_data=input('Would you like to subtract any data sets? Y/N');
if subtract_data == 1
higher=input('Enter the name of the spectrum you would like to subtract from');
lower=input('Enter the name of the spectrum you are subtracting');
new_data=higher-lower;
filename=input('Input file name: ', 's');

...?

end

I am not sure where to go from here how to get the variable new_data to be titled what the user inputs as filename.

thanks

You can use the eval function to evaluate text strings:
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/eval.html

>> bob = 'eye(3)'
>> eval(bob)

would run the command to create a 3x3 identity matrix. Really helpful (if inefficient) command since you can generate stuff on the fly, e.g. plotting a variable number of datasets on a 2D graph.
 
  • #3
for your question! It sounds like you are on the right track with your program. In order to have the user input the variable name, you can use the function "input" and include the variable name as a string in the prompt. For example, you can use the following code:

subtract_data = input('Would you like to subtract any data sets? Y/N');
if subtract_data == 1
higher = input('Enter the name of the spectrum you would like to subtract from: ');
lower = input('Enter the name of the spectrum you are subtracting: ');
new_data = higher - lower;
filename = input('Enter the name of the new variable: ', 's');
assignin('base', filename, new_data);
end

The "assignin" function allows you to assign a variable name to a value in the current workspace. In this case, we are assigning the value of "new_data" to the variable name specified by the user in the "filename" variable. This will create a new variable with the name specified by the user and assign it the value of the subtracted data. I hope this helps! Let me know if you have any other questions.
 

1. What is user input in Matlab?

User input in Matlab refers to data or values that are entered by the user during the execution of a program. These values can be stored in variables and used for calculations or other operations.

2. How do I prompt the user for input in Matlab?

To prompt the user for input in Matlab, you can use the input() function. This function takes in a string as an argument, which is displayed as a prompt to the user, and then waits for the user to enter a value. The value entered by the user can be stored in a variable for later use.

3. Can the user input variable name be changed in Matlab?

Yes, the user input variable name can be changed in Matlab. After using the input() function to store user input in a variable, you can use the rename() function to change the name of the variable. Alternatively, you can also use the assignment operator (=) to assign the user input to a new variable name.

4. How can I validate user input in Matlab?

You can validate user input in Matlab by using conditional statements such as if or switch. These statements allow you to check if the user input meets specific criteria, and if it does not, you can prompt the user to enter a different value. You can also use functions like isnumeric() or ischar() to check the type of the user input.

5. Is it possible to have multiple user inputs in Matlab?

Yes, it is possible to have multiple user inputs in Matlab. You can use the input() function multiple times to prompt the user for different values, and store them in separate variables. You can also use a loop, such as a for or while loop, to continuously prompt the user for input until a certain condition is met.

Similar threads

  • MATLAB, Maple, Mathematica, LaTeX
Replies
5
Views
1K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
2
Views
1K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
2
Views
1K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
4
Views
1K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
1
Views
2K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
2
Views
5K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
3
Views
1K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
5
Views
2K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
1
Views
1K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
3
Views
1K
Back
Top