Running examples in ‘occ-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: occ
> ### Title: Estimates PET neuroreceptor occupancies
> ### Aliases: occ occ.ols occ.ref occ.reml plot.occ print.occ
> ###   print.summary.occ summary.occ
> ### Keywords: maximum likelihood estimation neuroreceptor neuroreceptor
> ###   occupancy occupancy occupancy plot PET positron emission tomography
> ###   receptor receptor occupancy reference region restricted maximum
> ###   likelihood estimation
> 
> ### ** Examples
> 
> ## Total volumes of distribution (VT) from a simulated PET study
> ## including a baseline scan, as well as two other scans after
> ## administration of a drug. Note that each row in the matrix
> ## represents a ROI, whilst each column represents a scan.
> 
> data(occ.example)
> occ.example
                 Baseline 1st postdose 2nd postdose
Cerebellum           0.39         0.28         0.30
Frontal cortex       0.72         0.35         0.47
Occipital cortex     0.96         0.43         0.62
Parietal cortex      0.75         0.34         0.50
Temporal cortex      0.44         0.26         0.31
> 
> #                  Baseline 1st postdose 2nd postdose
> # Cerebellum           0.39         0.28         0.30
> # Frontal cortex       0.72         0.35         0.47
> # Occipital cortex     0.96         0.43         0.62
> # Parietal cortex      0.75         0.34         0.50
> # Temporal cortex      0.44         0.26         0.31
> 
> 
> ## Default REML fitting of these simulated data:
> 
> m = occ(occ.example)
> 
> print(m)     # Prints the neuroreceptor occupancy coefficients
$VT
                 Baseline 1st postdose 2nd postdose
Cerebellum           0.39         0.28         0.30
Frontal cortex       0.72         0.35         0.47
Occipital cortex     0.96         0.43         0.62
Parietal cortex      0.75         0.34         0.50
Temporal cortex      0.44         0.26         0.31

$coefficients
                 Baseline 1st postdose 2nd postdose
Cerebellum              0    0.7086362    0.4598614
Frontal cortex          0    0.7086362    0.4598614
Occipital cortex        0    0.7086362    0.4598614
Parietal cortex         0    0.7086362    0.4598614
Temporal cortex         0    0.7086362    0.4598614

$VND
     Baseline 1st postdose 2nd postdose
VND 0.1982597    0.1982597    0.1982597

$VS
                  Baseline 1st postdose 2nd postdose
Cerebellum       0.1964995    0.1964995    0.1964995
Frontal cortex   0.5177297    0.5177297    0.5177297
Occipital cortex 0.7678527    0.7678527    0.7678527
Parietal cortex  0.5491762    0.5491762    0.5491762
Temporal cortex  0.2325105    0.2325105    0.2325105

$sigma
        Baseline 1st postdose 2nd postdose
sigma 0.01016802   0.01016802   0.01016802

$fitted.values
                  Baseline 1st postdose 2nd postdose
Cerebellum       0.3947592    0.2555125    0.3043966
Frontal cortex   0.7159894    0.3491074    0.4779055
Occipital cortex 0.9661124    0.4219841    0.6130065
Parietal cortex  0.7474358    0.3582697    0.4948909
Temporal cortex  0.4307701    0.2660048    0.3238475

$residuals
                     Baseline  1st postdose 2nd postdose
Cerebellum       -0.004759197  0.0244874808 -0.004396649
Frontal cortex    0.004010596  0.0008926295 -0.007905481
Occipital cortex -0.006112358  0.0080158574  0.006993459
Parietal cortex   0.002564154 -0.0182697251  0.005109082
Temporal cortex   0.009229865 -0.0060048025 -0.013847546

$call
occ(VT = occ.example)

attr(,"class")
[1] "occ"
> 
> summary(m)   # Also prints the non-displaceable volume of
              Length Class  Mode   
VT            15     -none- numeric
coefficients  15     -none- numeric
VND            3     -none- numeric
VS            15     -none- numeric
sigma          3     -none- numeric
fitted.values 15     -none- numeric
residuals     15     -none- numeric
call           2     -none- call   
>              # distribution (VND), the specific volumes of
>              # distribution (VS) and the measurement error
> 
> fitted(m)    # Prints the fitted values
                  Baseline 1st postdose 2nd postdose
Cerebellum       0.3947592    0.2555125    0.3043966
Frontal cortex   0.7159894    0.3491074    0.4779055
Occipital cortex 0.9661124    0.4219841    0.6130065
Parietal cortex  0.7474358    0.3582697    0.4948909
Temporal cortex  0.4307701    0.2660048    0.3238475
> 
> residuals(m) # Prints the residuals
                     Baseline  1st postdose 2nd postdose
Cerebellum       -0.004759197  0.0244874808 -0.004396649
Frontal cortex    0.004010596  0.0008926295 -0.007905481
Occipital cortex -0.006112358  0.0080158574  0.006993459
Parietal cortex   0.002564154 -0.0182697251  0.005109082
Temporal cortex   0.009229865 -0.0060048025 -0.013847546
> 
> plot(m)      # Plots the estimated and observed volumes of
Error in xy.coords(x, y, xlabel, ylabel, log) : 
  'x' is a list, but does not have components 'x' and 'y'
Calls: plot -> plot.default -> xy.coords
Execution halted