The thing with julia is that most of the language is written in julia, so 
getting answers means just reading more julia code. So in GLM/src/lm.jl 
there is a function coeftable(..) that generates the above table. Taking 
the calculation from there, you get:

[ccdf(FDist(1,df_residual(lm1.model)),abs2(fval)) for fval in 
coef(lm1)./stderr(lm1)]

which gives the Pr(>|t|) column:
 0.551595  
 3.40919e-7

And as for how it is calculated - the formula shows it uses the F 
distribution.

On Tuesday, October 14, 2014 12:21:17 PM UTC+3, [email protected] wrote:
>
> In below example of GLM, I want to get the Pr(>|t|) value 3.4e-7. How can I 
> get it?
> Also, how this p-value be calculated? By F test or by Chisq test? I can 
> choose the test type in R but I can not choose in Julia.
>
> julia> using GLM, RDatasets
> julia> form = dataset("datasets","Formaldehyde")6x2 
> DataFrame|-------|------|--------|| Row # | Carb | OptDen || 1     | 0.1  | 
> 0.086  || 2     | 0.3  | 0.269  || 3     | 0.5  | 0.446  || 4     | 0.6  | 
> 0.538  || 5     | 0.7  | 0.626  || 6     | 0.9  | 0.782  |
> julia> lm1 = fit(LinearModel, OptDen ~ Carb, form)Formula: OptDen ~ Carb
> Coefficients:
>                Estimate  Std.Error  t value Pr(>|t|)(Intercept)  0.00508571 
> 0.00783368 0.649211   0.5516Carb           0.876286  0.0135345  64.7444   
> 3.4e-7
>
>

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