Rounding floats

General
1

Hi, guys. Can anyone tell me what is the best way to ROUND a float with 6 decimals to for instance a float with 2 decimals. ".Precision()", has the disadvantage that it includes the number of digits before the comma.

1 Like
2

Try
Math.round()

3

@E1cid , that will give me an integer.

4

sorry you are correct
try

Number(msg.payload.toFixed(2))

or

Math.round(float*100)/100
5

Why are you wanting to do this? If you are sending it to a dashboard node, for example, most of them allow you to do this at display time by using something like this in the Value Format field
{{msg.payload | number: 2}}
Generally numbers should not be rounded until they get to the display, it is not good to throw away accuracy before it is necessary.

2 Likes
6

The complex way, but does exactly what you wants.

var myvalue = 12.345678
var myvaluestr = myvalue.toString()
var index = myvaluestr.indexOf(".")
msg.payload= myvalue.toPrecision(index+2)

Gives 12.35

2 Likes
7

What is wrong with using ToFixed if it is necessary to do it in javascript? It should give exactly the same result without the additional code.

8

@Colin and @E1cid , you are completely right the both of you. I assumed that "Number" was truncating the float.Thanks for the answers.
To @edje11 , indeed your solution is complex and does the same, also thanks for your answer.

9

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.