glm2c {glm.deploy} | R Documentation |
C source code generator for rapid deployment of glm predictive models
Description
The glm2c()
function is used to generate source code in C language
implementing a given glm predictive model. It implements the following two functions;
the glm_xxx_response() and glm_xxx_link(), where xxx stands for the name of the target variable
of the glm object.
After the invocation of the glm2c()
function two files are generated:
A .c file with the two scoring functions.
An .h file with the prototypes of the two functions of the .c file.
Usage
glm2c(model, filename = NULL, path = NULL)
Arguments
model |
A fitted object of class "glm". |
filename |
OPTIONAL The name of the output file(s), the default filenames are "glm_xxx.c" and "glm_xxx.h", where xxx is the target variable's name. |
path |
The directory path where files are going to be saved. |
Note
All numeric variables used as input to the glm object are treated as doubles, whereas factor variables are treated as strings.
Author(s)
Oscar Castro-Lopez, Ines Vega-Lopez
See Also
Examples
# Example with the iris dataset with a Logical target and numeric variables,
# using the binomial family and the logit link function
data(iris)
iristest = iris
iristest$Virginica = ifelse(iristest$Species == 'virginica', TRUE,FALSE)
iristest$Species = NULL
# Load Package
library(glm.deploy)
# For repeatable results
set.seed(123)
# Generate the fitted glm object
m = glm(Virginica ~ ., family = binomial(logit), data=iristest)
# Call the glm2c() function with default filename
glm2c(m,,tempdir())
# Call the glm2c() function with custom filename
glm2c(m,'my_glm_virginica', tempdir())
# The glm2c() function generates the files: "glm_virginica.c" and
# "glm_virginica.h"
## Not run:
---------------Contents of the "glm_virgninica.c" file---------------
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
double glm_virginica_link(double sepal_length,
double sepal_width,
double petal_length,
double petal_width){
double new_sepal_length = -2.46522019518341 * sepal_length;
double new_sepal_width = -6.68088701405762 * sepal_width;
double new_petal_length = 9.4293851538836 * petal_length;
double new_petal_width = 18.2861368877881 * petal_width;
return -42.6378038127854+new_sepal_length+
new_sepal_width+
new_petal_length+
new_petal_width;
}
double glm_virginica_response(double sepal_length,
double sepal_width,
double petal_length,
double petal_width){
return 1/(1+exp(-glm_virginica_link(sepal_length,
sepal_width,
petal_length,
petal_width)));
}
----End of Contents of the "glm_virgninica.c" file------------------
--------------------------------------------------------------------
-----Contents of the "glm_virgninica.h" file------------------------
double glm_virginica_link(double sepal_length,
double sepal_width,
double petal_length,
double petal_width);
double glm_virginica_response(double sepal_length,
double sepal_width,
double petal_length,
double petal_width);
-----End of Contents of the "glm_virgninica.h" file-----------------
--------------------------------------------------------------------
Usage of the functions in another programs;
1) We need to add an include line #include "virginica_glm.h" to all
source files that use library definitions.
2) Link the .c file with the library object file.
gcc -c glm_virginica.c
3) The following is an example file "test.c" to call the functions
and print the result:
-------------------"test.c"---------------
#include <stdio.h>
#include "glm_virgnica.h" //Added to call the scoring functions.
int main(int argc, char *argv[]){
printf("%f\n",glm_virginica_link(5.7,2.5,5.0,2.0));
printf("%f\n",glm_virginica_response(5.7,2.5,5.0,2.0));
return 0;
}
---------------End of "test.c"---------------
---------------------------------------------
4) Compile the "test.c" file and link it to the glm_virginica shared
library, we also need to add the "-lm" option to link it to the
math.h library:
gcc test.c -o test glm_virginica.o -lm
5) Finally Run the test.o program in linux:
./test
## End(Not run)