# [R] R Matrix package solve

Matt Nunes Matt.Nunes at bristol.ac.uk
Mon Aug 9 15:33:52 CEST 2004

```torsten,

thanks for the mail.  I have reinstalled the Matrix package, but still get
the same problems.  Any ideas?

matt nunes.

--On 04 August 2004 3:26pm +0200 Torsten Hothorn
<Torsten.Hothorn at rzmail.uni-erlangen.de> wrote:

>
> On Wed, 4 Aug 2004, Matt Nunes wrote:
>
>> hello.
>>
>> I have a query about the Matrix package for R.  I wrote some code a while
>> ago using the Matrix package version 1.6.2 with an early version of R, to
>> do some linear least squares for regression:
>>
>> xn
>>      [,1]      [,2]      [,3]      [,4]
>> [1,]    1 0.7429352 0.5519528 0.4100652
>> [2,]    1 0.7443713 0.5540886 0.4124477
>> [3,]    1 0.7447385 0.5546355 0.4130584
>> [4,]    1 0.7459597 0.5564558 0.4150936
>> >
>> > temp<-crossprod(xn)
>> > temp
>>          [,1]     [,2]      [,3]      [,4]
>> [1,] 4.000000 2.978005 2.2171327 1.6506648
>> [2,] 2.978005 2.217133 1.6506648 1.2289297
>> [3,] 2.217133 1.650665 1.2289297 0.9149473
>> [4,] 1.650665 1.228930 0.9149473 0.6811865
>> >
>> > solve.Matrix(temp,t(xn))
>>            [,1]      [,2]      [,3]       [,4]
>> [1,]   33397.34  122081.7 -241005.4   85527.48
>> [2,]   21063.72 -664920.2  812316.0 -168459.99
>> [3,] -236935.74 1125548.2 -877776.2  -10835.64
>> [4,]  199314.69 -608045.8  297509.1  111221.72
>>
>> (Note:  here I used solve.Matrix since the generic solve said the matrix
>> is singular).
>>
>> I recently updated my versions of R to 1.9.1 and also the Matrix package,
>> but I can't seem to get any similar equivalent matrix calculations to
>> work (I get error messages like ".Call function name not in DLL for
>> package Matrix"
>
> this very much looks like a corrupted package installation. Try
> to reinstall  `Matrix'
>
> Torsten
>
>> or "Lapack routine dpotrf returned error code 4").  I have also
>> tried using symmetric matrix commands, but to no avail. Can anyone help
>> me out?
>>
>> many thanks
>>
>> Matt Nunes
>>
>>

```