topic Forecasting SPC Seasonally Adjusted in QlikView https://community.qlik.com/t5/QlikView/Forecasting-SPC-Seasonally-Adjusted/m-p/318576#M584088 <HTML><HEAD></HEAD><BODY><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">Hi All,</SPAN></P><P></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">I have managed to create liner trendlines using the following expression:</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">LINEST_M (TOTAL aggr(Sum(Refs),Month),Month)*Month+LINEST_B (TOTAL aggr(Sum(Refs),Month),Month)</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">However, I am interested in adding in seasonality to my data - for example I know that my data will drop off in December when there is less activity. Creating this in excel I would calculate the average monthly variance against the linear trendline and factor this against the forecasted trended data. The problem is that as my calculated dimension is Month this does not appear to work.</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">There is a field called 'M' which is the Month number - I assume though some kind of wizardry that this could be used to aggregate the data, but unfortunately it is currently beyond my ability.</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">Many thanks for any thoughts or workarounds.</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">Rich</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P></BODY></HTML> Thu, 06 Oct 2011 16:04:14 GMT 2011-10-06T16:04:14Z Forecasting SPC Seasonally Adjusted https://community.qlik.com/t5/QlikView/Forecasting-SPC-Seasonally-Adjusted/m-p/318576#M584088 <HTML><HEAD></HEAD><BODY><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">Hi All,</SPAN></P><P></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">I have managed to create liner trendlines using the following expression:</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">LINEST_M (TOTAL aggr(Sum(Refs),Month),Month)*Month+LINEST_B (TOTAL aggr(Sum(Refs),Month),Month)</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">However, I am interested in adding in seasonality to my data - for example I know that my data will drop off in December when there is less activity. Creating this in excel I would calculate the average monthly variance against the linear trendline and factor this against the forecasted trended data. The problem is that as my calculated dimension is Month this does not appear to work.</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">There is a field called 'M' which is the Month number - I assume though some kind of wizardry that this could be used to aggregate the data, but unfortunately it is currently beyond my ability.</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">Many thanks for any thoughts or workarounds.</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;">Rich</SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P><P><SPAN style="font-family: calibri, verdana, arial, sans-serif;"> </SPAN></P></BODY></HTML> Thu, 06 Oct 2011 16:04:14 GMT https://community.qlik.com/t5/QlikView/Forecasting-SPC-Seasonally-Adjusted/m-p/318576#M584088 2011-10-06T16:04:14Z