filename input into function

Really basic question, I have just started using MatLab. I have a function that pulls specific columns out of arrays that could be in any of four data files I am working with. Thus, my goal is to input a filename, have the function load the file, and then return the specific columns. Here is my current function:

function [tlat, trate] = lss_rr(filename)

G = load(filename)

m = G(:,3)

t = G(:,4)

But when I input a filename, the name returns as an undefined variable.

[Rik]

What exact code are you trying to run?

Answer 1

[Walter Roberson]

[TL, TR] = lss_rr('YourFile.txt');

Change YourFile.txt to the name of your file.

Do not try to use [TL, TR] = lss_rr(YourFile.txt); as that will try to evaluate YourFile as a variable.

Answer 2

[luis suarez]

When i type this command in matlab

function power_flow(filename)

Where filename is a .txt file

It says undefined variable. Can somebody help me please.

[Rik]

This is not an answer to this question. Also, this is a function definition, meaning that the variable filename will have the value with which you call the function.

[luis suarez]

@Rik I just want to ask a question about the same problem. That is as explained above. If you know how to call the txt file please answer me. In fact the txt file consists of some bus system parameters and i want to compute the power loss.

[Walter Roberson]

power_flow('NameOfYourTextFileGoesHere.txt')

[luis suarez]

Thank you very munch Mr walter Roberson it works now.