I'm trying to use fprinft in title because when i use the sprintf function it has way too many decimals. I keep getting error messages and i dont know how to fix them

subplot (2,2,1)
plot(X,Y)
z2= fprintf('Trajectory of projectile(v0= %2.0f\n and angle %2.0f\n)', v0, theta);
title(z2)
xlabel('Position in X direction (m)')
ylabel('Position in Y direction (m)')

Index exceeds the number of array elements (1).
Error in assigment03_pt01 (line 40)
title(z2)

[Stephen23]

"I'm trying to use fprinft in title because when i use the sprintf function it has way too many decimals"

fprintf and sprintf are not interchangeable:

• fprintf prints to a file or to the command window.
• sprintf prints to a character vector or scalar string.

They have exactly the same formatting options, so you gain absolutely nothing extra by swapping from one to the other, certainly no more or less control over decimal digits. As its documentation makes clear, the output of fprintf is a numeric count of the number of bytes printed: it is not clear why you want to provide this numeric count to title.

[Rik]

In addition to the points made by Stephen: the error hints that you have a scalar variable with the name title. Can you post the output of the following line of code to confirm this?

clc,which title -all

[BGN]

title is a variable.

C:\Program Files\MATLAB\R2019b\toolbox\matlab\graph2d\title.m % Shadowed

Index exceeds the number of array elements (1).

Error in assigment03_pt01 (line 41)

title(z2)

(i dont know how i made it a variable though)

[BGN]

nevermind, I just cleared the workspace and it somehow worked. Thank you all for helping me!

Answer 1

[Guillaume]

"I keep getting error messages"

Then read the doc of the functions you use, in particular pay close attention to what the inputs and outputs are.

For this particular error:

Index exceeds the number of array elements (1).
Error in assigment03_pt01 (line 40)
title(z2)

it would be because you have created a variable named title, so title(z2) is no longer passing z2 to the title function but instead is indexing into your title variable.

With regards to sprintf vs fprintf, as Stephen says you can't swap one for the other and in any case they format text exactly the same way (hence the very similar names). You want sprintf. Read the documentation of the format string to customise the display to what you want. Perhaps you want %g instead of %f.

"(i dont know how i made it a variable though)"

Somewhere, you wrote

title = something;