Ask MetaFilter questions tagged with sum

How do I sum all the combinations of a potential set of numbers?

geoff. — Sat, 09 May 2009 08:59:37 -0800

I have a group of numbers (4,5,10,53,1.5) and I want to display a graph showing the distribution of outcomes if I pick an arbitrary percent out of the the group and sum them. This has to be incredibly simple, what is the name for what I am trying to do? Or how can I do this in Excel? I think in mathematica you would total a subset which would just spit out a list, I didn't know if there was a way to do this in Excel and put in a nice chart showing like "this uses 10% of the numbers, this uses 100%" etc.

What's the next polynomial in this series?

Mapes — Tue, 27 Nov 2007 07:23:17 -0800

What's the next polynomial in this series: x⁴+2x²+16, x⁸+40x⁶+1128x⁴+2560x²+65536, ? I'm doing some work in elasticity and have found an analytical solution to a tricky problem. The solution is a converging infinite series, and I've been able to work out the first two terms (with great difficulty). It may be easier to guess the additional terms than work them out. The next polynomial almost certainly has seven terms, including x¹² and 2,176,782,336 (6¹²). Any guesses as to what the other coefficients are, and what the general pattern is?

(The sum converges because the denominators are (4+x²)^5/2, (16+x²)^9/2, ... and every other term is subtracted.)

All months, now.

tmcw — Thu, 15 Nov 2007 13:28:27 -0800

Sum of data for all months, including months with no rows, in MySQL? Hi, I've come across this problem a few times, and here's the thing:

I'll do a query, for instance, SUM(distance) for each month, group by month. This'll give me results with the sum of distance for each month with rows. But I'd like to present the sums of all months, including non-active months. So far my only option seems to be to create an array of months in PHP, iterate through that, and, for each month, search for a result in the MySQL query result. This works, but is there a cleaner design pattern, or a MySQL trick that might come in handy?
Thanks for any help.

excel macro n00b

beammeup4 — Mon, 02 Jul 2007 13:27:37 -0800

I need help writing a macro that will divide a 5000 row table into groups of 30 rows, and find the average of certain columns in each group. I've got a data table with blood pressure readings taken at 1-second intervals. I need help writing a macro that will take the table, divide the data into groups of 30 rows and spit out the average of certain columns in each group (I need one column for systolic, diastolic, MAP, etc., however, the table contains columns of irrelevant data), which will in effect give me averages other 30-second intervals.

To make things more complex, the actual readings start at row 48.

ExcelFilter: How do I display the sum within that column without resulting in a "circular reference" error?

chefscotticus — Fri, 29 Jun 2007 22:10:56 -0800

ExcelFilter: How do I display the sum within that column without resulting in a "circular reference" error? I'm building a spreadsheet to keep track of my paychecks. I'd like to keep track of YTD totals of a column (eg, federal taxes) at the top of that column, and find a formula that I can enter once into the top that will calculate the sum for the rest of the column for as many entries as I choose to make. Simply summing the entire column results in a circular reference error.

In other wods, for the simplified example below, give me a function for [SUM_FEDERAL] (in B1) that will sum the individual values for each cheque without me having to adjust/copy the function for each entry of a new cheque. (I know I could simply do =SUM(B4:B100), and adjust after 100 entries, but I want a solution that both scales and makes it simple to maintain).

AB
1YTD [SUM_FEDERAL]
2
3 Cheque No. &nbsp &nbspFederal
4015
5028
6037

I imagine that there is a super simple solution -- after several hours of playing around and searching Google, I've given up and turned to MeFi.