Thread::tdlen: Objects of unequal length

*To*: mathgroup at smc.vnet.net*Subject*: [mg121878] Thread::tdlen: Objects of unequal length*From*: SysInv <johan at systeminvestors.se>*Date*: Wed, 5 Oct 2011 04:04:36 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

This problem is driving me crazy. I'm trying to multiply matrices, where one is 1x4 (s) and the other is 4x4 (t) and the multiplication is s*t*Transpose[s] Despite this I get the error message that the objects is of unequal length. The matrices are: s={{x1,x2,x3,x4}} t={0.0284435,0.00395759,0.000211963,0.0357403},{0.00395759,0.0113862,-0.000199939,-0.000556137},{0.000211963,-0.000199939,0.00118147,-0.00043913},{ 0.0357403,-0.000556137,-0.00043913,0.0649449} I must use double level in the 1 row matrix, since otherwise Transpose[] complains that it needs at least 2 levels. I tried without this as well, but I keep getting: Thread::tdlen : Objects of unequal length in {{x1,x2,x3,x4}}{{0.0284435,0.00395759,0.000211963,0.0357403},<<2>>,{<<10>>,<<3>>}}{{x1},{x2},{x3},{x4}} cannot be combined. >> . when I run s*t*Transpose[s]. I've spent hours trying to figure this simple problem out, but without any luck. Any pointers guys? It doesn't help if I change the order of the transpose...

**Follow-Ups**:**Re: Thread::tdlen: Objects of unequal length***From:*Leonid Shifrin <lshifr@gmail.com>

**Re: Thread::tdlen: Objects of unequal length***From:*DrMajorBob <btreat1@austin.rr.com>

**Re: Thread::tdlen: Objects of unequal length***From:*Heike Gramberg <heike.gramberg@gmail.com>

**Re: Thread::tdlen: Objects of unequal length***From:*Vivek Joshi <vivekjjoshi29@gmail.com>

**Re: Thread::tdlen: Objects of unequal length***From:*Tomas Garza <tgarza10@msn.com>

**Re: Thread::tdlen: Objects of unequal length***From:*Sseziwa Mukasa <mukasa@gmail.com>