From where did you obtain the code for the biomaRt workflow? - one of my posts? If you use that, then you need to select a different attribute, because, in that code that you have pasted, you are assuming that the probe IDs are derived from the 'Affymetrix U133 Plus 2.0'; however, you have the 'Affymetrix U95 Version 2'. You can find attributes via biomaRt like this:
listAttributes(mart)[grep("affy", listAttributes(mart)[,1]),] name description page 104 affy_hc_g110 AFFY HC G110 probe feature_page 105 affy_hg_focus AFFY HG Focus probe feature_page 106 affy_hg_u133a AFFY HG U133A probe feature_page 107 affy_hg_u133a_2 AFFY HG U133A 2 probe feature_page 108 affy_hg_u133b AFFY HG U133B probe feature_page 109 affy_hg_u133_plus_2 AFFY HG U133 Plus 2 probe feature_page 110 affy_hg_u95a AFFY HG U95A probe feature_page 111 affy_hg_u95av2 AFFY HG U95Av2 probe feature_page 112 affy_hg_u95b AFFY HG U95B probe feature_page 113 affy_hg_u95c AFFY HG U95C probe feature_page 114 affy_hg_u95d AFFY HG U95D probe feature_page 115 affy_hg_u95e AFFY HG U95E probe feature_page 116 affy_hta_2_0 AFFY HTA 2 0 probe feature_page 117 affy_huex_1_0_st_v2 AFFY HuEx 1 0 st v2 probe feature_page 118 affy_hugenefl AFFY HuGeneFL probe feature_page 119 affy_hugene_1_0_st_v1 AFFY HuGene 1 0 st v1 probe feature_page 120 affy_hugene_2_0_st_v1 AFFY HuGene 2 0 st v1 probe feature_page 121 affy_primeview AFFY PrimeView probe feature_page 122 affy_u133_x3p AFFY U133 X3P probe feature_page
...so, you will want to use
As to whether or not the general code will work, please take time to examine what each line is doing, make QC checks, and then make an 'executive' decision about whether or not it is doing what you want. To me, it looks like the code will do what you want it to do, but please do check yourself.
Regarding the other code that you have pasted using hgu95av2.db, I am not so sure... You simply have to do something like the following:
library(hgu95av2.db) mapIds( hgu95av2.db, c('991_g_at','976_s_at','954_s_at', 'hhh', '39167_r_at'), keytype="PROBEID", column = 'SYMBOL') 'select()' returned 1:1 mapping between keys and columns 991_g_at 976_s_at 954_s_at hhh 39167_r_at "FLT1" "MAPK1" "PPP1CA" NA "SERPINH1"
I added a dummy probe ID, 'hhh', just to show you that it returns NA when no match is found.