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

> ### Name: IRT.truescore
> ### Title: Converts a theta Score into a True Score tau ( theta)
> ### Aliases: IRT.truescore
> 
> ### ** Examples
> 
> #############################################################################
> # EXAMPLE 1: True score conversion for a test with polytomous items
> #############################################################################
> 
> data(data.Students, package="CDM")
> dat <- data.Students[, paste0("mj",1:4) ]
> 
> # fit partial credit model
> mod1 <- TAM::tam.mml( dat,control=list(maxiter=20) )
....................................................
Processing Data      2021-12-02 20:55:08 
    * Response Data: 2400 Persons and  4 Items 
    * Numerical integration with 21 nodes
    * Created Design Matrices   ( 2021-12-02 20:55:08 )
    * Calculated Sufficient Statistics   ( 2021-12-02 20:55:08 )
....................................................
Iteration 1     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 20499.2631
  Maximum item intercept parameter change: 0.562054
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.486617
....................................................
Iteration 2     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 20105.4515 | Absolute change: 393.8116 | Relative change: 0.0195873
  Maximum item intercept parameter change: 0.206128
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.35712
....................................................
Iteration 3     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 19944.2336 | Absolute change: 161.2179 | Relative change: 0.00808343
  Maximum item intercept parameter change: 0.207467
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.360083
....................................................
Iteration 4     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 19822.6875 | Absolute change: 121.5461 | Relative change: 0.00613167
  Maximum item intercept parameter change: 0.193255
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.356844
....................................................
Iteration 5     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 19733.5628 | Absolute change: 89.1247 | Relative change: 0.0045164
  Maximum item intercept parameter change: 0.171963
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.340186
....................................................
Iteration 6     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 19669.3356 | Absolute change: 64.2272 | Relative change: 0.00326534
  Maximum item intercept parameter change: 0.152592
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.314329
....................................................
Iteration 7     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 19624.3371 | Absolute change: 44.9986 | Relative change: 0.002293
  Maximum item intercept parameter change: 0.13107
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.280392
....................................................
Iteration 8     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 19593.3973 | Absolute change: 30.9398 | Relative change: 0.00157909
  Maximum item intercept parameter change: 0.111203
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.243661
....................................................
Iteration 9     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 19572.5719 | Absolute change: 20.8253 | Relative change: 0.00106401
  Maximum item intercept parameter change: 0.092884
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.206905
....................................................
Iteration 10     2021-12-02 20:55:08
E Step
M Step Intercepts   |----
  Deviance = 19558.7926 | Absolute change: 13.7794 | Relative change: 0.00070451
  Maximum item intercept parameter change: 0.076677
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.172435
....................................................
Iteration 11     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19549.7968 | Absolute change: 8.9957 | Relative change: 0.00046015
  Maximum item intercept parameter change: 0.062737
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.141668
....................................................
Iteration 12     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19543.9844 | Absolute change: 5.8124 | Relative change: 0.0002974
  Maximum item intercept parameter change: 0.050949
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.114982
....................................................
Iteration 13     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19540.2487 | Absolute change: 3.7357 | Relative change: 0.00019118
  Maximum item intercept parameter change: 0.041233
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.092517
....................................................
Iteration 14     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19537.855 | Absolute change: 2.3937 | Relative change: 0.00012252
  Maximum item intercept parameter change: 0.033314
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.073949
....................................................
Iteration 15     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19536.3194 | Absolute change: 1.5356 | Relative change: 7.86e-05
  Maximum item intercept parameter change: 0.026862
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.058895
....................................................
Iteration 16     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19535.332 | Absolute change: 0.9874 | Relative change: 5.055e-05
  Maximum item intercept parameter change: 0.021656
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.046795
....................................................
Iteration 17     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19534.6945 | Absolute change: 0.6375 | Relative change: 3.263e-05
  Maximum item intercept parameter change: 0.01742
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.037109
....................................................
Iteration 18     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19534.2805 | Absolute change: 0.414 | Relative change: 2.119e-05
  Maximum item intercept parameter change: 0.014093
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.029415
....................................................
Iteration 19     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19534.0093 | Absolute change: 0.2712 | Relative change: 1.388e-05
  Maximum item intercept parameter change: 0.011381
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.02315
....................................................
Iteration 20     2021-12-02 20:55:09
E Step
M Step Intercepts   |----
  Deviance = 19533.8292 | Absolute change: 0.1801 | Relative change: 9.22e-06
  Maximum item intercept parameter change: 0.009215
  Maximum item slope parameter change: 0
  Maximum regression parameter change: 0
  Maximum variance parameter change: 0.018311
....................................................
Item Parameters
   xsi.index xsi.label     est
1          1  mj1_Cat1 -4.2876
2          2  mj1_Cat2 -2.6936
3          3  mj1_Cat3  0.1857
4          4  mj2_Cat1 -3.7349
5          5  mj2_Cat2 -1.0935
6          6  mj2_Cat3  1.3039
7          7  mj3_Cat1 -2.1422
8          8  mj3_Cat2  0.3272
9          9  mj3_Cat3  1.9774
10        10  mj4_Cat1 -2.6496
11        11  mj4_Cat2 -0.0615
12        12  mj4_Cat3  1.8041
...................................
Regression Coefficients
     [,1]
[1,]    0

Variance:
      [,1]
[1,] 4.755


EAP Reliability:
[1] 0.841

-----------------------------
Start:  2021-12-02 20:55:08
End:  2021-12-02 20:55:09 
Time difference of 0.1842797 secs

> summary(mod1)
------------------------------------------------------------
TAM 3.7-16 (2021-06-24 14:31:37) 
R Under development (unstable) (2021-12-02 r81283) x86_64, linux-gnu | nodename=gannet.stats.ox.ac.uk | login=ripley 

Date of Analysis: 2021-12-02 20:55:09 
Time difference of 0.1842797 secs
Computation time: 0.1842797 

Multidimensional Item Response Model in TAM 

IRT Model: 1PL
Call:
TAM::tam.mml(resp = dat, control = list(maxiter = 20))

------------------------------------------------------------
Number of iterations = 20 
Numeric integration with 21 integration points

Deviance = 19533.83 
Log likelihood = -9766.91 
Number of persons = 2400 
Number of persons used = 2371 
Number of items = 4 
Number of estimated parameters = 13 
    Item threshold parameters = 12 
    Item slope parameters = 0 
    Regression parameters = 0 
    Variance/covariance parameters = 1 

AIC = 19560  | penalty=26    | AIC=-2*LL + 2*p 
AIC3 = 19573  | penalty=39    | AIC3=-2*LL + 3*p 
BIC = 19635  | penalty=101.02    | BIC=-2*LL + log(n)*p 
aBIC = 19594  | penalty=59.7    | aBIC=-2*LL + log((n-2)/24)*p  (adjusted BIC) 
CAIC = 19648  | penalty=114.02    | CAIC=-2*LL + [log(n)+1]*p  (consistent AIC) 
AICc = 19560  | penalty=26.15    | AICc=-2*LL + 2*p + 2*p*(p+1)/(n-p-1)  (bias corrected AIC) 
GHP = 1.04308     | GHP=( -LL + p ) / (#Persons * #Items)  (Gilula-Haberman log penalty) 

------------------------------------------------------------
EAP Reliability
[1] 0.841
------------------------------------------------------------
Covariances and Variances
      [,1]
[1,] 4.755
------------------------------------------------------------
Correlations and Standard Deviations (in the diagonal)
      [,1]
[1,] 2.181
------------------------------------------------------------
Regression Coefficients
     [,1]
[1,]    0
------------------------------------------------------------
Item Parameters -A*Xsi
Error in Math.data.frame(list(item = c("mj1", "mj2", "mj3", "mj4"), N = c(2351,  : 
  non-numeric-alike variable(s) in data frame: item
Calls: summary ... tam_round_data_frame_print -> tam_round_data_frame -> Math.data.frame
Execution halted