Problem with fprintf - invalid file intentifier

So i have calculated some variables (X and Y) and i'm trying to insert them in a txt file. The .syn extension is for the exercise that i have. The error tham i'm getting is : Invalid file identifier. Use fopen to generate a valid file identifier. Anyone knows what's wrong?

Answer 1

[Walter Roberson]

The filename you construct from the user's input together with the suffix .syn names a file that is not present in the current directory or anywhere on the MATLAB path and the user did not provide an appropriate path as part of their input.

This could for example happen if the user already provided the .syn extension. You always add a .syn extension so you could end up with NAME.syn.syn

[Mohamed Imbaby]

Yes, when i'm running the code i put only the name of the file without the extension .syn and the problem that i wrote before occurs. For the directory i have created a folder where i store all the files of the problem and the text with the .syn extension that i created. Should i provide the path of the file that i created with a different way? Any idea on how to do it? Thank you in advance.

[Mohamed Imbaby]

You were right, the direction was wrong and i changed it and it works! Thank you!