More robust fixes for numerical issues

Makefile

@@ -1,6 +1,6 @@
 CXX ?= g++
 CFLAGS = -Wall -Wconversion -O3 -fPIC
-SHVER = 4
+SHVER = 5
 OS = $(shell uname)
 ifeq ($(OS),Darwin)
 	SHARED_LIB_FLAG = -dynamiclib -Wl,-install_name,libsvm.so.$(SHVER)

matlab/svmtrain.c

@@ -46,6 +46,9 @@ void exit_with_help()
 	"-e epsilon : set tolerance of termination criterion (default 0.001)\n"
 	"-h shrinking : whether to use the shrinking heuristics, 0 or 1 (default 1)\n"
 	"-b probability_estimates : whether to train a SVC or SVR model for probability estimates, 0 or 1 (default 0)\n"
+	"-f floatprecision : set the floating-point precision of kernel values (default 0)\n"
+	"  0 -- float\n"
+	"  1 -- double\n"
 	"-wi weight : set the parameter C of class i to weight*C, for C-SVC (default 1)\n"
 	"-v n: n-fold cross validation mode\n"
 	"-q : quiet mode (no outputs)\n"
@@ -125,6 +128,7 @@ int parse_command_line(int nrhs, const mxArray *prhs[], char *model_file_name)
 	param.p = 0.1;
 	param.shrinking = 1;
 	param.probability = 0;
+	param.use_double_precision_kernel_values = 0;
 	param.nr_weight = 0;
 	param.weight_label = NULL;
 	param.weight = NULL;
@@ -187,6 +191,9 @@ int parse_command_line(int nrhs, const mxArray *prhs[], char *model_file_name)
 			case 'b':
 				param.probability = atoi(argv[i]);
 				break;
+			case 'f':
+			   param.use_double_precision_kernel_values = atoi(argv[i]);
+			   break;
 			case 'q':
 				print_func = &print_null;
 				i--;

python/libsvm/svm.py

@@ -240,10 +240,10 @@ def __init__(self, y, x, isKernel=False):
 class svm_parameter(Structure):
     _names = ["svm_type", "kernel_type", "degree", "gamma", "coef0",
             "cache_size", "eps", "C", "nr_weight", "weight_label", "weight",
-            "nu", "p", "shrinking", "probability"]
+            "nu", "p", "shrinking", "probability", "use_double_precision_kernel_values"]
     _types = [c_int, c_int, c_int, c_double, c_double,
             c_double, c_double, c_double, c_int, POINTER(c_int), POINTER(c_double),
-            c_double, c_double, c_int, c_int]
+            c_double, c_double, c_int, c_int, c_int]
     _fields_ = genFields(_names, _types)
 
     def __init__(self, options = None):
@@ -274,6 +274,7 @@ def set_to_default_values(self):
         self.p = 0.1
         self.shrinking = 1
         self.probability = 0
+        self.use_double_precision_kernel_values = 0
         self.nr_weight = 0
         self.weight_label = None
         self.weight = None
@@ -331,6 +332,9 @@ def parse_options(self, options):
             elif argv[i] == "-b":
                 i = i + 1
                 self.probability = int(argv[i])
+            elif argv[i] == '-f':
+                i = i + 1
+                self.use_double_precision_kernel_values = int(argv[i])
             elif argv[i] == "-q":
                 self.print_func = PRINT_STRING_FUN(print_null)
             elif argv[i] == "-v":

python/libsvm/svmutil.py

@@ -84,6 +84,9 @@ def svm_train(arg1, arg2=None, arg3=None):
         -e epsilon : set tolerance of termination criterion (default 0.001)
         -h shrinking : whether to use the shrinking heuristics, 0 or 1 (default 1)
         -b probability_estimates : whether to train a model for probability estimates, 0 or 1 (default 0)
+	     -f floatprecision : set the floating-point precision of kernel values (default 0)
+	         0 -- float
+	         1 -- double
         -wi weight : set the parameter C of class i to weight*C, for C-SVC (default 1)
         -v n: n-fold cross validation mode
         -q : quiet mode (no outputs)

svm-train.c

@@ -35,6 +35,9 @@ void exit_with_help()
 	"-e epsilon : set tolerance of termination criterion (default 0.001)\n"
 	"-h shrinking : whether to use the shrinking heuristics, 0 or 1 (default 1)\n"
 	"-b probability_estimates : whether to train a SVC or SVR model for probability estimates, 0 or 1 (default 0)\n"
+	"-f floatprecision : set the floating-point precision of kernel values (default 0)\n"
+	"  0 -- float\n"
+	"  1 -- double\n"
 	"-wi weight : set the parameter C of class i to weight*C, for C-SVC (default 1)\n"
 	"-v n: n-fold cross validation mode\n"
 	"-q : quiet mode (no outputs)\n"
@@ -176,6 +179,7 @@ void parse_command_line(int argc, char **argv, char *input_file_name, char *mode
 	param.p = 0.1;
 	param.shrinking = 1;
 	param.probability = 0;
+	param.use_double_precision_kernel_values = 0;
 	param.nr_weight = 0;
 	param.weight_label = NULL;
 	param.weight = NULL;
@@ -225,6 +229,9 @@ void parse_command_line(int argc, char **argv, char *input_file_name, char *mode
 			case 'b':
 				param.probability = atoi(argv[i]);
 				break;
+			case 'f':
+			   param.use_double_precision_kernel_values = atoi(argv[i]);
+			   break;
 			case 'q':
 				print_func = &print_null;
 				i--;