Matrix inversion - size of Matrix

Iceman

New Member
Joined
Nov 15, 2002
Messages
2
I've found through a brief trial and error that the largest matrix I can invert (Excel:mac, by the way) is 49x49.

I would like to invert larger matrices (very useful for engineering problems like finite difference thermal modelling, where the matrix size limits how complicated a model you can build) and wondered if this is a hard limit, is machine specific or whatever?

Many thanks
 

Some videos you may like

Excel Facts

Can a formula spear through sheets?
Use =SUM(January:December!E7) to sum E7 on all of the sheets from January through December

Aladin Akyurek

MrExcel MVP
Joined
Feb 14, 2002
Messages
85,201
On 2002-11-16 13:45, Iceman wrote:
I've found through a brief trial and error that the largest matrix I can invert (Excel:mac, by the way) is 49x49.

I would like to invert larger matrices (very useful for engineering problems like finite difference thermal modelling, where the matrix size limits how complicated a model you can build) and wondered if this is a hard limit, is machine specific or whatever?

Many thanks

If you have access to a Windows machine, you could use the morefunc.xll add-in which has extended matrix functions, e.g., MINVERSE.EXT for 256x256.
 

kelvin

New Member
Joined
Nov 17, 2002
Messages
19
Merci M. laurent - les adjonctions sont perfect!

***

While the MINVERSE.EXT worked for my application (I was unable to invert beyond 51x51), the function is limited to 256 columns in width (the natural limit of the sheet obviously) and so, 256 rows in depth as well.

If you really need to invert larger forms, one could always try partitioning the larger matrix into smaller sub-matrices.

See this link for a "quick and dirty" review of inverting partitioned matrices:

http://www.cc.utah.edu/~nahaj/math/matrix.inverse.notes.html

Note:

A is m x m,
B is m x n,
C is n x m, and
D is n x n

only the A and D partitions need be inverted and are presumeably of managable size.

****

Here's another question though... When will Excel expand beyond the current 256 column limitation? It seems to me that today's computers could handle much more than that (say Column ZZ ---> 676 columns) even if we had to sacrifice some of the thousands of rows that I only use rarely.
 

Aladin Akyurek

MrExcel MVP
Joined
Feb 14, 2002
Messages
85,201
kelvin said:
...Here's another question though... When will Excel expand beyond the current 256 column limitation? It seems to me that today's computers could handle much more than that (say Column ZZ ---> 676 columns) even if we had to sacrifice some of the thousands of rows that I only use rarely.

Looking at it from a database angle, having 256 fields should be adequate.
 

Watch MrExcel Video

Forum statistics

Threads
1,122,559
Messages
5,596,836
Members
414,107
Latest member
Tigretto

We've detected that you are using an adblocker.

We have a great community of people providing Excel help here, but the hosting costs are enormous. You can help keep this site running by allowing ads on MrExcel.com.
Allow Ads at MrExcel

Which adblocker are you using?

Disable AdBlock

Follow these easy steps to disable AdBlock

1)Click on the icon in the browser’s toolbar.
2)Click on the icon in the browser’s toolbar.
2)Click on the "Pause on this site" option.
Go back

Disable AdBlock Plus

Follow these easy steps to disable AdBlock Plus

1)Click on the icon in the browser’s toolbar.
2)Click on the toggle to disable it for "mrexcel.com".
Go back

Disable uBlock Origin

Follow these easy steps to disable uBlock Origin

1)Click on the icon in the browser’s toolbar.
2)Click on the "Power" button.
3)Click on the "Refresh" button.
Go back

Disable uBlock

Follow these easy steps to disable uBlock

1)Click on the icon in the browser’s toolbar.
2)Click on the "Power" button.
3)Click on the "Refresh" button.
Go back
Top