Array indices must be positive integers or logical values. error for simple calculation, nothing array related

Hello, forgive me for this probably dumb question. I am super new to matlab and at the moment I am just trying to use Matlab for tedious calculations. Can you guys help figure out why this error shows up when I am just doing simple calculations? Thank you very much.

My code:

v1 = (4*5*10^-4)/(pi*(0.01)^2);
v2 = (4*5*10^-4)/(pi*(0.02)^2);
g = 9.81;
hb = 2;

deltaH = 1/g(0.5*v1^2-g*hb-0.5*v2^2) - 2.01;

Array indices must be positive integers or logical values.

[Walter Roberson]

For future reference:

MATLAB does not permit implied multiplication anywhere

Answer 1

[Umang Pandey]

Hi William,

The error is because while you are trying to divide the "deltaH" expression by "g", it is instead getting treated as an array instead.

You can reformulate it in the following manner -

v1 = (4*5*10^-4)/(pi*(0.01)^2); 
v2 = (4*5*10^-4)/(pi*(0.02)^2); 
g = 9.81;  
hb = 2;  
deltaH = (0.5*v1^2 - g*hb - 0.5*v2^2)/g - 2.01; 

Hope this helps!

Best,

Umang

[Stephen23]

"... it is instead getting treated as a function instead."

The error message explains that g is being indexed into as an array.

[Umang Pandey]

Hi Stephen, thanks for the correction! I made a typo I meant to say an array!

[William]

Thank you guys, that makes sense now. Really appreciate it.