Decimal Places by Condition

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1

Table Example

 

start_date val ---------------------------------------- 2022.05.02D07:36:35.901000000 0.01 2022.05.02D07:36:36.341000000 0.0125 2022.05.02D07:36:36.756000000 0.01234568 2022.05.02D07:36:37.204000000 0.9999 2022.05.02D07:36:37.636000000 0.008

 

 

 

Desired Result

 

start_date val ---------------------------------------- 2022.05.02D07:36:35.901000000 0.01 2022.05.02D07:36:36.341000000 0.013 2022.05.02D07:36:36.756000000 0.012 2022.05.02D07:36:37.204000000 1 2022.05.02D07:36:37.636000000 0.008

 

 

 

I tried follows.

 

@[meter;`val;.Q.f[3]'] start_date val ------------------------------------- 2022.05.02D07:36:35.901000000 “0.010” 2022.05.02D07:36:36.341000000 “0.013” 2022.05.02D07:36:36.756000000 “0.012” 2022.05.02D07:36:37.204000000 “1.000” 2022.05.02D07:36:37.636000000 “0.008”

 

 

 

How do I create a function to represent the desired result?

The \P is set to zero.

2

 

q)show val:.01 .0125 .01234568 .9999 .008 0.01 0.0125 0.01234568 0.9999 0.008 q).001floor .5+1000val 0.01 0.013 0.012 1 0.008

 

More generally, as a function which takes number of decimal places as its left argument:

 

q){%[;s]floor .5+y*s:10 xexp x}[3]val 0.01 0.013 0.012 1 0.008

 

Slightly less obviously you can elide floor .5+ with a faster Cast:

 

 

q){%[;s]“i”$y*s:10 xexp x}[3]val 0.01 0.013 0.012 1 0.008

 

3

Thanks!