topic Iteratively identify sample based on changing totals in SAS Programming https://communities.sas.com/t5/SAS-Programming/Iteratively-identify-sample-based-on-changing-totals/m-p/753498#M237497 <P>Hi,</P><P>Currently this selection is done manually so I have no code to share. I believe I can automate the process in SAS and I thought it would be good to ask here in case anyone can give me some pointers. I have looked for like questions but didn't find anything.</P><P>&nbsp;</P><P>The end goal is to identify a sample that represents group characteristics with as few of the observations as possible. Based on group totals formulas and rounding are used to generate a list of “need” characteristic totals. After an observation is selected to be a part of the sample they need to be deducted from the needed count (Need_initial), until a sample is selected that represents the total desired count for each characteristic.</P><P>&nbsp;</P><P>I have added a pretend dataset that represents a group. In the table below I put the initial total counts (Need initial), an example of an observation selected for the sample, and then how that first selection impacted the needed totals (Need_2).&nbsp;Sometimes subcategory counts may not be in line with the category total. For example, in this case the sample only needs 1 observation with patterns but the sample should include 1 pattern_dots and 1 pattern_plaid regardless of whether that combination can be identified within one observation.</P><P>&nbsp;</P><TABLE><TBODY><TR><TD>&nbsp;</TD><TD><P>Need_Initial</P></TD><TD><P>Selection_1</P></TD><TD><P>Need_2</P></TD></TR><TR><TD><P>Dinner</P></TD><TD><P>14</P></TD><TD><P>1</P></TD><TD><P>13</P></TD></TR><TR><TD><P>Likes_talking</P></TD><TD><P>8</P></TD><TD><P>1</P></TD><TD><P>7</P></TD></TR><TR><TD><P>Visiting</P></TD><TD><P>8</P></TD><TD><P>1</P></TD><TD><P>7</P></TD></TR><TR><TD><P>Hates_talking</P></TD><TD><P>7</P></TD><TD><P>0</P></TD><TD><P>7</P></TD></TR><TR><TD><P>Green</P></TD><TD><P>3</P></TD><TD><P>0</P></TD><TD><P>3</P></TD></TR><TR><TD><P>Dark_Yellow</P></TD><TD><P>3</P></TD><TD><P>1</P></TD><TD><P>2</P></TD></TR><TR><TD><P>Dark_Green</P></TD><TD><P>2</P></TD><TD><P>1</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Dark_White</P></TD><TD><P>2</P></TD><TD><P>0</P></TD><TD><P>2</P></TD></TR><TR><TD><P>Blue</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Yellow</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR><TR><TD><P>White</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Red</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Black</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR><TR><TD><P>Grey</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Light_Blue</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Light_orange</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Light_red</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Dark_Black</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR><TR><TD><P>Patterns</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR><TR><TD><P>Pattern_Dots</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Pattern_Plaid</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR></TBODY></TABLE><P>&nbsp;</P> Mon, 12 Jul 2021 13:37:23 GMT Zen_aly 2021-07-12T13:37:23Z Iteratively identify sample based on changing totals https://communities.sas.com/t5/SAS-Programming/Iteratively-identify-sample-based-on-changing-totals/m-p/753498#M237497 <P>Hi,</P><P>Currently this selection is done manually so I have no code to share. I believe I can automate the process in SAS and I thought it would be good to ask here in case anyone can give me some pointers. I have looked for like questions but didn't find anything.</P><P>&nbsp;</P><P>The end goal is to identify a sample that represents group characteristics with as few of the observations as possible. Based on group totals formulas and rounding are used to generate a list of “need” characteristic totals. After an observation is selected to be a part of the sample they need to be deducted from the needed count (Need_initial), until a sample is selected that represents the total desired count for each characteristic.</P><P>&nbsp;</P><P>I have added a pretend dataset that represents a group. In the table below I put the initial total counts (Need initial), an example of an observation selected for the sample, and then how that first selection impacted the needed totals (Need_2).&nbsp;Sometimes subcategory counts may not be in line with the category total. For example, in this case the sample only needs 1 observation with patterns but the sample should include 1 pattern_dots and 1 pattern_plaid regardless of whether that combination can be identified within one observation.</P><P>&nbsp;</P><TABLE><TBODY><TR><TD>&nbsp;</TD><TD><P>Need_Initial</P></TD><TD><P>Selection_1</P></TD><TD><P>Need_2</P></TD></TR><TR><TD><P>Dinner</P></TD><TD><P>14</P></TD><TD><P>1</P></TD><TD><P>13</P></TD></TR><TR><TD><P>Likes_talking</P></TD><TD><P>8</P></TD><TD><P>1</P></TD><TD><P>7</P></TD></TR><TR><TD><P>Visiting</P></TD><TD><P>8</P></TD><TD><P>1</P></TD><TD><P>7</P></TD></TR><TR><TD><P>Hates_talking</P></TD><TD><P>7</P></TD><TD><P>0</P></TD><TD><P>7</P></TD></TR><TR><TD><P>Green</P></TD><TD><P>3</P></TD><TD><P>0</P></TD><TD><P>3</P></TD></TR><TR><TD><P>Dark_Yellow</P></TD><TD><P>3</P></TD><TD><P>1</P></TD><TD><P>2</P></TD></TR><TR><TD><P>Dark_Green</P></TD><TD><P>2</P></TD><TD><P>1</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Dark_White</P></TD><TD><P>2</P></TD><TD><P>0</P></TD><TD><P>2</P></TD></TR><TR><TD><P>Blue</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Yellow</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR><TR><TD><P>White</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Red</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Black</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR><TR><TD><P>Grey</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Light_Blue</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Light_orange</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Light_red</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Dark_Black</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR><TR><TD><P>Patterns</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR><TR><TD><P>Pattern_Dots</P></TD><TD><P>1</P></TD><TD><P>0</P></TD><TD><P>1</P></TD></TR><TR><TD><P>Pattern_Plaid</P></TD><TD><P>1</P></TD><TD><P>1</P></TD><TD><P>0</P></TD></TR></TBODY></TABLE><P>&nbsp;</P> Mon, 12 Jul 2021 13:37:23 GMT https://communities.sas.com/t5/SAS-Programming/Iteratively-identify-sample-based-on-changing-totals/m-p/753498#M237497 Zen_aly 2021-07-12T13:37:23Z Re: Iteratively identify sample based on changing totals https://communities.sas.com/t5/SAS-Programming/Iteratively-identify-sample-based-on-changing-totals/m-p/753580#M237540 <P>This looks like a constrained optimization problem. The "need" characteristics are constraints. The number of observations in the data set is&nbsp;a quantity that you are trying to minimize, subject to the constraints.</P> <P>&nbsp;</P> <P>Do you have a license for SAS/OR software? Or SAS/IML?</P> Mon, 12 Jul 2021 18:15:03 GMT https://communities.sas.com/t5/SAS-Programming/Iteratively-identify-sample-based-on-changing-totals/m-p/753580#M237540 Rick_SAS 2021-07-12T18:15:03Z Re: Iteratively identify sample based on changing totals https://communities.sas.com/t5/SAS-Programming/Iteratively-identify-sample-based-on-changing-totals/m-p/753582#M237541 <P>It looks like I do have SAS/IML!</P> Mon, 12 Jul 2021 18:37:01 GMT https://communities.sas.com/t5/SAS-Programming/Iteratively-identify-sample-based-on-changing-totals/m-p/753582#M237541 Zen_aly 2021-07-12T18:37:01Z