Forecasting

Summing and Averaging

February 10, 2021

The Sum function in MetrixND seems like a complex way to make adding difficult.

In a MetrixND transformation, numbers are added by joining variables with the “+” sign. Adding three variables is as simple as writing the following expression in the transformation editor formula box:

DataSource.Variable1 + DataSource.Variable2 + DataSource.Variable3

The complex way to add is using the “Sum” function. This function requires inserting the three variables separated by commas (,) as Sum function parameters, as shown below:

Sum(DataSource.Variable1,DataSource.Variable2,DataSource.Variable3)

Technically speaking, the Sum function requires five extra characters to do the same work as the traditional “+” sign.

So, why does MetrixND include this function?

In the situation where variables have missing values, the calculation using the “+” sign results in a missing value. In other words, a number plus a missing value equals a missing value.

100 + MISSING = MISSING

While the Sum function behaves the same, the Ignore Missing option changes the behavior to produce a value. In other words, the Sum function with the Ignore Missing option selected means that a number plus a missing value equals a number.

100 + MISSING = 100

To activate the Ignore Missing option, check the Ignore Missing box in the transformation editor as shown below.

The Ignore Missing options works with the following functions:

  • Sum
  • Avg
  • Max
  • Min

It doesn’t matter whether you use traditional math operators or the functions when data is complete. However, when the dataset has missing values, the functions and Ignore Missing options may be the difference between forecasting a number and forecasting a MISSING.

Complexity has its purpose.

Kesalahan terjadi ketika Memproses Template.
The following has evaluated to null or missing:
==> authorContent.contentFields  [in template "44616#44647#114455" at line 9, column 17]

----
Tip: It's the step after the last dot that caused this error, not those before it.
----
Tip: If the failing expression is known to legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
----

----
FTL stack trace ("~" means nesting-related):
	- Failed at: contentFields = authorContent.content...  [in template "44616#44647#114455" at line 9, column 1]
----
1<#assign 
2	webContentData = jsonFactoryUtil.createJSONObject(author.getData()) 
3	classPK = webContentData.classPK 
4/> 
5 
6<#assign 
7authorContent = restClient.get("/headless-delivery/v1.0/structured-contents/" + classPK + "?fields=contentFields%2CfriendlyUrlPath%2CtaxonomyCategoryBriefs") 
8contentFields = authorContent.contentFields 
9categories=authorContent.taxonomyCategoryBriefs 
10authorContentData = jsonFactoryUtil.createJSONObject(authorContent) 
11friendlyURL = authorContentData.friendlyUrlPath 
12authorCategoryId = "0" 
13/> 
14 
15<#list contentFields as contentField > 
16   <#assign  
17	 contentFieldData = jsonFactoryUtil.createJSONObject(contentField)  
18	 name = contentField.name 
19	 /> 
20	 <#if name == 'authorImage'> 
21	    <#if (contentField.contentFieldValue.image)??> 
22	        <#assign authorImageURL = contentField.contentFieldValue.image.contentUrl />	 
23			</#if> 
24	 </#if> 
25	 <#if name == 'authorName'> 
26	    <#assign authorName = contentField.contentFieldValue.data /> 
27			<#list categories as category > 
28         <#if authorName == category.taxonomyCategoryName> 
29				     <#assign authorCategoryId = category.taxonomyCategoryId /> 
30				 </#if> 
31      </#list> 
32	 </#if> 
33	 <#if name == 'authorDescription'> 
34	    <#assign authorDescription = contentField.contentFieldValue.data /> 
35			 
36	 </#if> 
37	  
38	 <#if name == 'authorJobTitle'> 
39	    <#assign authorJobTitle = contentField.contentFieldValue.data /> 
40			 
41	 </#if> 
42 
43</#list> 
44 
45<div class="blog-author-info"> 
46	<#if authorImageURL??> 
47		<img class="blog-author-img" id="author-image" src="${authorImageURL}" alt="" /> 
48	</#if> 
49	<#if authorName??> 
50		<#if authorName != ""> 
51			<p class="blog-author-name">By <a id="author-detail-page" href="/w/${friendlyURL}?filter_category_552298=${authorCategoryId}"><span id="author-full-name">${authorName}</span></a></p> 
52			<hr /> 
53		</#if> 
54	</#if> 
55	<#if authorJobTitle??> 
56		<#if authorJobTitle != ""> 
57			<p class="blog-author-title" id="author-job-title" >${authorJobTitle}</p> 
58			<hr /> 
59		</#if> 
60	</#if> 
61	<#if authorDescription??> 
62		<#if authorDescription != "" && authorDescription != "null" > 
63			<p class="blog-author-desc" id="author-job-desc">${authorDescription}</p> 
64			<hr /> 
65		</#if> 
66	</#if> 
67</div>