Bradley, you’re forgetting about interactions terms.

 — John

On Aug 31, 2014, at 12:53 PM, Bradley Setzler <[email protected]> wrote:

> No problem.
> 
> Honestly, I'm not sure formula is a useful way to think about regression, the 
> formula is uniquely determined from:
> (depVar, indepVars, data, family, link)
> 
> so that the + symbols are redundant given family and link,
> glm(Y ~ X1 + X2 + X3 + X4 + X5 +...., family, link)
> 
> and it would be nice to have an explicit intercept argument like,
> glm(Y,X,data,family,link,intercept=true)
> 
> Adding to the wish list, I would like to see something like a series option 
> for non-parametric regression,
> glm(Y,X,data,family,link,seriesRank=2)
> where seriesRank=2 means all of the terms X1.^2, X1.*X2, X1.*X3,...,X5.^2 are 
> included as regressors.
> 
> Bradley
> 
> 
> 
> 
> On Sunday, August 31, 2014 2:32:30 PM UTC-5, John Myles White wrote:
> Merged. Thanks, Bradley.
> 
>  — John
> 
> On Aug 31, 2014, at 12:29 PM, Bradley Setzler <[email protected]> wrote:
> 
>> Thank you for suggesting this, John.
>> 
>> https://github.com/JuliaStats/GLM.jl/pull/90
>> 
>> Bradley
>> 
>> 
>> On Sunday, August 31, 2014 1:33:04 PM UTC-5, John Myles White wrote:
>> Bradley, it’s especially easy to edit documentation because you can make a 
>> Pull Request right from the website.
>> 
>>  — John
>> 
>> On Aug 31, 2014, at 11:30 AM, Bradley Setzler <[email protected]> wrote:
>> 
>>> Thank you Adam, this works.
>>> 
>>> Let me suggest that this information be included in the GLM documentation:
>>> 
>>> To fit a GLM model, use the function,
>>> glm(formula, data, family, link), 
>>> where,
>>> - formula uses column symbols from the DataFrame data, e.g., if 
>>> names(data)=[:Y,:X], then a valid formula is Y~X;
>>> - data is a DataFrame which may contain NA values, the rows with NA values 
>>> will be ignored (apparently);
>>> - family may be chosen from Binomial(), Gamma(), Normal(), or Poisson(), 
>>> and the parentheses are required; and,
>>> - link may be chosen from the list in the GLM documentation, such as 
>>> LogitLink(), and again the parentheses are required. For some families, a 
>>> default link is available so the link argument may be left blank.
>>> 
>>> Bradley
>>> 
>>> 
>>> On Sunday, August 31, 2014 12:56:19 PM UTC-5, Adam Kapor wrote:
>>> This works for me:
>>> 
>>> ```
>>> julia> fit(GeneralizedLinearModel,Y~X,data,Binomial(),ProbitLink())
>>> 
>>> DataFrameRegressionModel{GeneralizedLinearModel,Float64}:
>>> 
>>> Coefficients:
>>> 
>>>                 Estimate Std.Error     z value Pr(>|z|)
>>> 
>>> (Intercept)     0.430727   1.98019    0.217518   0.8278
>>> 
>>> X            2.37745e-17   0.91665 2.59362e-17   1.0000
>>> 
>>> julia> fit(GeneralizedLinearModel,Y~X,data,Binomial(),LogitLink())
>>> 
>>> DataFrameRegressionModel{GeneralizedLinearModel,Float64}:
>>> 
>>> Coefficients:
>>> 
>>>                  Estimate Std.Error      z value Pr(>|z|)
>>> 
>>> (Intercept)      0.693147   3.24037      0.21391   0.8306
>>> 
>>> X            -7.44332e-17       1.5 -4.96221e-17   1.0000
>>> 
>>> ```
>>> 
>>> 
>>> On Sunday, August 31, 2014 1:27:15 PM UTC-4, Bradley Setzler wrote:
>>> Has anyone successfully performed probit or logit regression in Julia? The 
>>> GLM documentation does not provide a generalizable example of how to use 
>>> glm(). It gives a Poisson example without any suggestion of how to switch 
>>> from Poisson to some other type.
>>> 
>>> Using the Poisson example from GLM documentation works:
>>> 
>>> julia> X = [1;2;3.]
>>> julia> Y = [1;0;1.]
>>> julia> data = DataFrame(X=X,Y=Y)
>>> julia> fit(GeneralizedLinearModel, Y ~ X,data, Poisson())
>>> DataFrameRegressionModel{GeneralizedLinearModel,Float64}: 
>>> Coefficients: 
>>> Estimate Std.Error z value Pr(>|z|) 
>>> (Intercept) -0.405465 1.87034 -0.216787 0.8284 
>>> X -3.91448e-17 0.8658 -4.52123e-17 1.0000 
>>> 
>>> But does not generalize:
>>> 
>>> julia> fit(GeneralizedLinearModel, Y ~ X ,data, Logit()) 
>>> ERROR: Logit not defined
>>> 
>>> julia> fit(GeneralizedLinearModel, Y ~ X, data, link=:ProbitLink) 
>>> ERROR: `fit` has no method matching fit(::Type{GeneralizedLinearModel}, 
>>> ::Array{Float64,2}, ::Array{Float64,1})
>>> 
>>> julia> fit(GeneralizedLinearModel, Y ~ X, data, 
>>> family="binomial",link="probit") 
>>> ERROR: `fit` has no method matching fit(::Type{GeneralizedLinearModel}, 
>>> ::Array{Float64,2}, ::Array{Float64,1})
>>> 
>>> ....and a dozen other similar attempts fail. 
>>> 
>>> 
>>> Thanks,
>>> Bradley
>>> 
>> 
> 

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