Mathematical operations in Octave

In this lesson, I'll explain what are the operators that allow you to perform the main mathematical operations on Octave.

Addition

The addition operator is +

>> 3+2
ans = 5

Subtraction

The subtraction operator is -

>> 3-2
ans = 1

Multiplication

Multiplication multiplication operator is

>> 4*2
ans = 8c

Division

The division operator is /

>> 8/2
ans = 4

Remainder of the Division

To calculate the remainder of the division use the mod() function

>> mod(7,2)
ans = 1

Warning. Unlike many programming languages, the Octave software does not use the percent symbol % to calculate the remainder of division, because the % symbol is used to write comments. So if you write 7%2 the software treats 2 as a comment and returns 7 as the result. Therefore, if you need to calculate the modulus of division you must use the mod() function.

Power

The power operator is ^

>> 2^3
ans = 8

Alternatively, you can also use the double asterisk to calculate the exponentiation of a number

>> 2**3
ans = 8

Square root

To calculate the square root you have to use the function sqrt()

>> sqrt(16)
ans = 4

Alternatively you can raise the number by the fraction 1/2

>> 16**(1/2)
ans = 4

In addition to these basic math operators, there are many other Octave functions that allow you to perform many other math operations

• abs(x)
  returns the absolute value of x
• cos(x)
  calculate the cosine of x
• sin(x)
  calculate the sine of x
• tan(x)
  calculate the tangent of x
• acos(x)
  calculates the arc cosine of x
• asin(x)
  calculate the arcsine of x
• atan(x)
  compute the arc tangent x
• exp(x)
  calculate the exponential of x
• log(x)
  calculate the natural logarithm of
• log10(x)
  calculate the base 10 logarithm of x
• sqrt(x)
  calculate the square root of x
• nthroot(x,n)
  calculate the nth real root of x

For example to calculate the absolute value you can use the abs() function

>> abs(-1)
ans = 1

In general, Octave results are displayed in short format with 5 significant digits by default.

However, you can change the number format (long/short) or use scientific notation.