[R] Replacing all NA values in a matrix

[Sean Davis]

You have it already....

 > h <- matrix(rnorm(100),nrow=20)
 > h
             [,1]       [,2]        [,3]         [,4]       [,5]
  [1,]  0.4669801  0.3349176 -1.60686041  0.981491440  0.1627222
  [2,] -0.2580262 -0.2620413  0.53852801  1.294129626 -0.1632906
  [3,]  0.9654591  1.0077212 -0.45603772  1.845272884  0.2910091
  [4,]  1.0710281  1.6234312  0.19610087  0.524864299 -0.1197756
  [5,]  0.3727526 -1.0742054 -0.46485338 -0.128577874  0.5177477
  [6,]  0.7289514  1.9020074  0.34534408 -0.313550835  0.7026291
  [7,] -0.3037257  0.3922162 -1.77990093  0.596858216 -0.4039951
  [8,] -1.7857808  0.4271333 -1.32907071 -0.596656935  0.4008593
  [9,]  1.4643707 -0.4369587  0.93522859 -0.948929936  0.1416290
[10,]  0.1243959 -1.4509269 -0.39656577 -0.550951866  1.2189326
[11,]  0.7210016 -0.2337671  0.70075393 -1.034782089 -1.7652139
[12,]  0.5509319 -0.9731717  0.12392721  0.421338123 -1.3197952
[13,]  1.8718778 -0.2853116  0.69003178  0.939630649  0.7421644
[14,] -0.3897884 -1.4627226 -0.32424877  1.115026790 -0.3912558
[15,] -1.5784201  0.6987771 -0.29907714  0.816135639 -0.8182227
[16,] -0.6140077 -0.1025945  0.04281918  0.006010866  1.0701661
[17,] -1.0290960  0.1830102 -0.51057604 -1.034981163 -1.5717075
[18,] -0.0902371  1.6820050 -0.40896428 -1.560638110  1.1076107
[19,] -1.6744785  2.2675648  0.27397118  1.223144752 -0.9754583
[20,] -0.2265682  0.1512010  0.60412290  0.585478462  0.5247539
 > h[h<0] <- NA
 > h
            [,1]      [,2]       [,3]        [,4]      [,5]
  [1,] 0.4669801 0.3349176         NA 0.981491440 0.1627222
  [2,]        NA        NA 0.53852801 1.294129626        NA
  [3,] 0.9654591 1.0077212         NA 1.845272884 0.2910091
  [4,] 1.0710281 1.6234312 0.19610087 0.524864299        NA
  [5,] 0.3727526        NA         NA          NA 0.5177477
  [6,] 0.7289514 1.9020074 0.34534408          NA 0.7026291
  [7,]        NA 0.3922162         NA 0.596858216        NA
  [8,]        NA 0.4271333         NA          NA 0.4008593
  [9,] 1.4643707        NA 0.93522859          NA 0.1416290
[10,] 0.1243959        NA         NA          NA 1.2189326
[11,] 0.7210016        NA 0.70075393          NA        NA
[12,] 0.5509319        NA 0.12392721 0.421338123        NA
[13,] 1.8718778        NA 0.69003178 0.939630649 0.7421644
[14,]        NA        NA         NA 1.115026790        NA
[15,]        NA 0.6987771         NA 0.816135639        NA
[16,]        NA        NA 0.04281918 0.006010866 1.0701661
[17,]        NA 0.1830102         NA          NA        NA
[18,]        NA 1.6820050         NA          NA 1.1076107
[19,]        NA 2.2675648 0.27397118 1.223144752        NA
[20,]        NA 0.1512010 0.60412290 0.585478462 0.5247539
 > h[is.na(h)] <- 0
 > h
            [,1]      [,2]       [,3]        [,4]      [,5]
  [1,] 0.4669801 0.3349176 0.00000000 0.981491440 0.1627222
  [2,] 0.0000000 0.0000000 0.53852801 1.294129626 0.0000000
  [3,] 0.9654591 1.0077212 0.00000000 1.845272884 0.2910091
  [4,] 1.0710281 1.6234312 0.19610087 0.524864299 0.0000000
  [5,] 0.3727526 0.0000000 0.00000000 0.000000000 0.5177477
  [6,] 0.7289514 1.9020074 0.34534408 0.000000000 0.7026291
  [7,] 0.0000000 0.3922162 0.00000000 0.596858216 0.0000000
  [8,] 0.0000000 0.4271333 0.00000000 0.000000000 0.4008593
  [9,] 1.4643707 0.0000000 0.93522859 0.000000000 0.1416290
[10,] 0.1243959 0.0000000 0.00000000 0.000000000 1.2189326
[11,] 0.7210016 0.0000000 0.70075393 0.000000000 0.0000000
[12,] 0.5509319 0.0000000 0.12392721 0.421338123 0.0000000
[13,] 1.8718778 0.0000000 0.69003178 0.939630649 0.7421644
[14,] 0.0000000 0.0000000 0.00000000 1.115026790 0.0000000
[15,] 0.0000000 0.6987771 0.00000000 0.816135639 0.0000000
[16,] 0.0000000 0.0000000 0.04281918 0.006010866 1.0701661
[17,] 0.0000000 0.1830102 0.00000000 0.000000000 0.0000000
[18,] 0.0000000 1.6820050 0.00000000 0.000000000 1.1076107
[19,] 0.0000000 2.2675648 0.27397118 1.223144752 0.0000000
[20,] 0.0000000 0.1512010 0.60412290 0.585478462 0.5247539
 >

Sean

On Jan 5, 2005, at 9:26 AM, michael watson ((IAH-C)) wrote:

> OK, dumb question, and it is probably in the docs somewhere, but after
> 12 months working with R and quite a while looking at the docs, I still
> don't know (or have forgotten) how to replace all NA values in a matrix
> at once with some other value.  I can do it column by column using
> is.na(), but I can't figure out how to do it for the whole matrix.  My
> apologies, I am ashamed ;-)
>
> Michael Watson
> Head of Informatics
> Institute for Animal Health,
> Compton Laboratory,
> Compton,
> Newbury,
> Berkshire RG20 7NN
> UK
>
> Phone : +44 (0)1635 578411 ext. 2535
> Mobile: +44 (0)7990 827831
> E-mail: michael.watson at bbsrc.ac.uk
>
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