Using Conditions and the Splice Function to Replace "if" Statements

[Morgan Bowling]

We often do calculations where we are interested in having one result if one condition is true and a second result if another condition is true.  In this post we will discuss how to do this calculation in Seeq. 

We will create a new single signal which runs different calculations during different periods of time. This technique can be used to replicate "if" logic or "if / else" logic currently being used in excel.

Example existing code from excel or other systems

• IF Temperature > 90 then show a result of  (Temperature * 100) 
• IF Temperature < 90F then show a result of  (Temperature + 10)

Step 1: Identify two modes of operation

• In the Tools tab identify the following conditions using the Value Search tool:

 

 

Step 2: Use formula to reconstruct "if/then statement" using Seeq's Splice Tool

Variables:

Name	Item	Type
$Temperature	Temperature	Signal
$HighTempCondition	Greater than 90	Condition

Seeq Formula:

 

$HighTempCalc = $Temperature * 100
$LowTempCalc = $Temperature + 10

$LowTempCalc.splice($HighTempCalc,$HighTempCondition)

 

Section 1  -  $HighTempCalc
This is the first arbitrary calculation which is to be run during periods of high temperature

Section 2  -  $LowTempCalc
This is the first arbitrary calculation which is to be run when NOT in periods of high temperature

Final  -  $LowTempCalc.splice($HighTempCalc,$HighTempCondition)
Combine your two series. Use the LowTempCalc series, unless you are in the High Temperature condition, in which case use the HighTempCalc 

 

 

 

[Lindsey.Wilcox]

If the condition(s) used in the analysis have a maximum capsule duration that is greater than 30 days, an alternative method is recommended to replace "if" statements.  If this is the case, users can use boolean signals, as described in the following post:

 

[Ingrid]

Why this isn't working?

[Thorsten Vogt]

Hi Ingrid,

you try to use splice on a scalar, which is available since R51. In lesser versions you can apply splice only on signals, so changing $h to a signal first should resolve the issue:

$h.tosignal().splice($l, $lfc)

Regards,

Thorsten