how insert decimal number in ubuntu?

Question

How can I multiply by decimal numbers and get the result in decimal?? How can the code be modified to meet these two conditions?

Answer 1

You could call the desk-calculator program to do the arithmetic:

v1 = 3
pi = 3.14
$ echo "Area of Circle =" $(dc --expression="$pi $v1 * $v1 * p")
Area of Circle = 28.26

In case you aren't familiar with it, dc uses reverse-polish syntax:

• stack $pi
• stack $v1
• replace the top two numbers with their product
• stack $v1
• replace the top two numbers with their product
• print the top of the stack

These are equivalent expressions:

$ echo "Area of Circle =" $(dc --expression="$pi $v1 * $v1 * p")
Area of Circle = 28.26
$ echo "Area of Circle =" $(dc --expression="$pi $v1 2 ^ * p")
Area of Circle = 28.26
$ echo "Area of Circle =" $(dc --expression="$v1 2 ^ $pi * p")
Area of Circle = 28.26