IDEAScripting and More - statistics
http://ideascripting.com/tags/statistics
enZ-score
http://ideascripting.com/content/z-score
<div class="field field-name-field-background field-type-text-with-summary field-label-above"><div class="field-label">Background: </div><div class="field-items"><div class="field-item even"><p>Calculates the z-score of a selected numerical field. The user has the option of having the analysis performed based on the population standard deviation or the sample standard deviation.</p></div></div></div><div class="field field-name-field-documentation field-type-text-with-summary field-label-above"><div class="field-label">Documentation: </div><div class="field-items"><div class="field-item even"><p>Script: z-score.iss</p>
<p>Author: Brian Element - <a href="mailto:brian.element@ideascripting.com">brian.element@ideascripting.com</a></p>
<p>Date: August 16, 2012</p>
<p>Purpose: This script creates a new field in your database and will calculate the z-score for the selected field.</p>
<p>Per Wikipeadia a z-score "indicates by how many standard deviations an observation or datum is above or below the main".</p>
<p>In a normal bell-shaped curve approximately 95% of your observations would fall to within two standard deviations on the mean. 99.7% of your observations would fall within three standard deviations of your mean. The z-score is a good indicator of how closely an observation would be to the mean, the smaller the number the closer it is to the mean.</p>
<p>When starting the script you will be given the following dialog.</p>
<p><img src="/sites/default/files/zscore.jpg" height="345" width="340"></p>
<p>You must first select the file you wish to perform the analysis on and then select a numeric field to have the z-score calculated on. You have a choice of either the population or the sample standard deviation. You would generally select population if you have the complete population to review, if you only have a sample of the population you would select sample standard deviation.</p>
<p>The script creates an additional field called Z_SCORE. The closer the Z_SCORE is to 0 the closer it is to the mean (which can be found in the field statistics). If the Z_SCORE is +/- 1 then that means that the observation is one standard deviation from the mean, if it is +/- 2 it would be two standard deviations and so on. The larger the Z_SCORE the farther the observation is from the mean, this can be used to look for unusually large or small amounts.</p></div></div></div><div class="field field-name-field-document-pdf field-type-file field-label-above"><div class="field-label">Document PDF: </div><div class="field-items"><div class="field-item even"><span class="file"><img class="file-icon" alt="PDF icon" title="application/pdf" src="/modules/field/file/icons/application-pdf.png" /> <a href="http://ideascripting.com/sites/default/files/z-score.pdf" type="application/pdf; length=13061">z-score.pdf</a></span></div></div></div><div class="field field-name-field-tags1 field-type-taxonomy-term-reference field-label-above clearfix"><h3 class="field-label">Tags: </h3><ul class="links"><li class="taxonomy-term-reference-0"><a href="/tags/v85" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">v8.5</a></li><li class="taxonomy-term-reference-1"><a href="/tags/statistics" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">statistics</a></li></ul></div>Thu, 16 Aug 2012 16:42:45 +0000Brian Element88 at http://ideascripting.comhttp://ideascripting.com/content/z-score#comments