int8(3) vs int(3)

When I try run int(3), or int('b') I get an error: Undefined function 'int' for input arguments of type 'char'.

But when I run int8(3) or int8('b') (or any other int type) I get the expected results. Why?

Answer 1

[Hugo]

At least in Matlab 2015, the function "int" is related to filters (in the filtstates package) or integration (in the symbolic package) but not to casting data types.

The functions for converting data, including "int8" are described in

MATLAB > Language Fundamentals > Operators and Elementary Operations > Arithmetic > Integers

in the Matlab documentation.

Hope this helps.

[Galen Elias]

Thanks for your help!

Answer 2

[Geoff Hayes]

Galen - int is not a built-in MATLAB function. In the Command Window, type

 which int -all

and you will see the message

 'int' not found.

This makes sense because in order to cast something to an integer you need to specify the number of bits used in that (new) integer. That is why int8 works as it will convert a value to an 8-bit signed integer. Likewise, there exist functions to convert/cast the data to 16-, 32-, and 64-bit signed integers. Equivalent functions exist for converting/casting to unsigned integers.

[Galen Elias]

Great answer thank you so much