[R] NaN

[Brett Stansfield]

Dear R
What does NaN mean?
I recently did a correlation on a batch of data for some reason it didn't
like one column
cor(sleep,use="complete.obs")
                 BodyWt     BrainWt  SlowSleep   ParaSleep TotalSleep
BodyWt       1.00000000  0.95584875 -0.3936373 -0.07488845 -0.3428373
BrainWt      0.95584875  1.00000000 -0.3867947 -0.07427740 -0.3370815
SlowSleep   -0.39363729 -0.38679474  1.0000000  0.51824287  0.9676730
ParaSleep   -0.07488845 -0.07427740  0.5182429  1.00000000  0.7171864
TotalSleep  -0.34283732 -0.33708151  0.9676730  0.71718643  1.0000000
Lifespan     0.46982146  0.62938940 -0.3722345 -0.26834006 -0.3824462
Gestation    0.71434413  0.73353206 -0.6061048 -0.40893177 -0.6144743
PredIndex    0.09588524 -0.01538017 -0.3526558 -0.39795310 -0.4047155
ExposeIndex  0.40563880  0.32318968 -0.5802789 -0.50363338 -0.6213578
DangerIndex  0.25932512  0.15093686 -0.5346247 -0.57194862 -0.6043029
logbrw       0.47461094  0.53992522 -0.6302266 -0.36884187 -0.6223073
loglife      0.37351520  0.45819097 -0.3549184 -0.38521174 -0.4028017
loggest      0.41308558  0.45045240 -0.5754478 -0.57234786 -0.6376850
logbw        0.50905390  0.52255094 -0.6603217 -0.26930774 -0.6174775
logpara             NaN         NaN        NaN         NaN        NaN
               Lifespan   Gestation   PredIndex ExposeIndex DangerIndex
BodyWt       0.46982146  0.71434413  0.09588524   0.4056388  0.25932512
BrainWt      0.62938940  0.73353206 -0.01538017   0.3231897  0.15093686
SlowSleep   -0.37223446 -0.60610477 -0.35265576  -0.5802789 -0.53462471
ParaSleep   -0.26834006 -0.40893177 -0.39795310  -0.5036334 -0.57194862
TotalSleep  -0.38244618 -0.61447431 -0.40471545  -0.6213578 -0.60430286
Lifespan     1.00000000  0.64638866 -0.16973575   0.3157456  0.01468596
Gestation    0.64638866  1.00000000  0.09079823   0.5734727  0.30623551
PredIndex   -0.16973575  0.09079823  1.00000000   0.6256876  0.92731729
ExposeIndex  0.31574564  0.57347265  0.62568764   1.0000000  0.78980702
DangerIndex  0.01468596  0.30623551  0.92731729   0.7898070  1.00000000
logbrw       0.73584286  0.78178948  0.07112786   0.6132218  0.28600619
loglife      0.87677362  0.63260838 -0.09023386   0.5042496  0.14082719
loggest      0.56014783  0.88539870  0.09040680   0.5830778  0.30998808
logbw        0.64683285  0.75938272  0.13046983   0.6473671  0.33957121
logpara             NaN         NaN         NaN         NaN         NaN
                 logbrw     loglife    loggest      logbw logpara
BodyWt       0.47461094  0.37351520  0.4130856  0.5090539     NaN
BrainWt      0.53992522  0.45819097  0.4504524  0.5225509     NaN
SlowSleep   -0.63022657 -0.35491836 -0.5754478 -0.6603217     NaN
ParaSleep   -0.36884187 -0.38521174 -0.5723479 -0.2693077     NaN
TotalSleep  -0.62230729 -0.40280169 -0.6376850 -0.6174775     NaN
Lifespan     0.73584286  0.87677362  0.5601478  0.6468328     NaN
Gestation    0.78178948  0.63260838  0.8853987  0.7593827     NaN
PredIndex    0.07112786 -0.09023386  0.0904068  0.1304698     NaN
ExposeIndex  0.61322176  0.50424965  0.5830778  0.6473671     NaN
DangerIndex  0.28600619  0.14082719  0.3099881  0.3395712     NaN
logbrw       1.00000000  0.79233406  0.7771888  0.9514144     NaN
loglife      0.79233406  1.00000000  0.6417551  0.7079108     NaN
loggest      0.77718882  0.64175514  1.0000000  0.7069276     NaN
logbw        0.95141435  0.70791078  0.7069276  1.0000000     NaN
logpara             NaN         NaN        NaN        NaN       1

for some reason log para has this NaN symbol come up