#include <math.h>
#endif
+#define LAMBDA_STEP 0.01
+
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_lagrange, surf,
"Logging specific to SURF (lagrange)");
+XBT_LOG_NEW_SUBCATEGORY(surf_writelambda, surf,
+ "Generates the lambda.in file. WARNING: the size of this file might be a few GBs.");
+
+void lagrange_solve(lmm_system_t sys);
+
void lagrange_solve(lmm_system_t sys)
{
-
/*
* Lagrange Variables.
*/
- double epsilon_min_error = 1e-6;
+ int max_iterations= 1000000;
+ double epsilon_min_error = 0.00001;
double overall_error = 1;
- double sigma_step = 0.5e-3;
- double capacity_error, bound_error;
- double sum_capacity = 0;
- double sum_bound = 0;
-
+ double sigma_step = LAMBDA_STEP;
+ //double capacity_error=0, bound_error=0;
+ int watch_out = 0;
/*
* Variables to manipulate the data structure proposed to model the maxmin
* fairness. See docummentation for more details.
*/
- lmm_element_t elem = NULL;
+ xbt_swag_t elem_list = NULL;
+ //lmm_element_t elem = NULL;
+ lmm_element_t elem1 = NULL;
+
+
xbt_swag_t cnst_list = NULL;
+ //lmm_constraint_t cnst = NULL;
lmm_constraint_t cnst1 = NULL;
- lmm_constraint_t cnst2 = NULL;
+ //lmm_constraint_t cnst2 = NULL;
+
+
xbt_swag_t var_list = NULL;
- xbt_swag_t elem_list = NULL;
+ //lmm_variable_t var = NULL;
lmm_variable_t var1 = NULL;
lmm_variable_t var2 = NULL;
-
/*
* Auxiliar variables.
*/
int iteration=0;
- int max_iterations=100000;
double mu_partial=0;
double lambda_partial=0;
+ double tmp=0;
+ int i,j;
+ FILE *gnuplot_file=NULL;
+ //char print_buf[1024];
+ //char *trace_buf=xbt_malloc0(sizeof(char));
+ //double sum;
+
+
+ DEBUG0("Iterative method configuration snapshot =====>");
+ DEBUG1("#### Maximum number of iterations : %d", max_iterations);
+ DEBUG1("#### Minimum error tolerated : %e", epsilon_min_error);
+ DEBUG1("#### Step : %e", sigma_step);
if ( !(sys->modified))
return;
-
+
/*
* Initialize the var list variable with only the active variables.
- * Associate an index in the swag variables and compute the sum
- * of all round trip time constraints. May change depending on the
- * function f(x).
+ * Associate an index in the swag variables. Initialize mu.
*/
- var_list = &(sys->active_variable_set);
+ var_list = &(sys->variable_set);
i=0;
xbt_swag_foreach(var1, var_list) {
- if(var1->weight != 0.0){
- i++;
- sum_bound += var1->bound;
+ if((var1->bound > 0.0) || (var1->weight <= 0.0)){
+ DEBUG1("#### NOTE var1(%d) is a boundless variable", i);
+ var1->mu = -1.0;
+ } else{
+ var1->mu = 1.0;
+ var1->new_mu = 2.0;
}
+ DEBUG2("#### var1(%d)->mu: %e", i, var1->mu);
+ DEBUG2("#### var1(%d)->weight: %e", i, var1->weight);
+ i++;
}
/*
- * Compute the sum of all capacities constraints. May change depending
- * on the function f(x).
+ * Initialize lambda.
*/
cnst_list=&(sys->active_constraint_set);
xbt_swag_foreach(cnst1, cnst_list) {
- sum_capacity += cnst1->value;
+ cnst1->lambda = 1.0;
+ cnst1->new_lambda = 2.0;
+ DEBUG2("#### cnst1(%p)->lambda: %e", cnst1, cnst1->lambda);
+ }
+
+ if(XBT_LOG_ISENABLED(surf_writelambda, xbt_log_priority_debug)) {
+ gnuplot_file = fopen("lambda.in", "w");
+ fprintf(gnuplot_file, "# iteration lambda1 lambda2 lambda3 ... lambdaP\n");
}
* While doesn't reach a minimun error or a number maximum of iterations.
*/
while(overall_error > epsilon_min_error && iteration < max_iterations){
-
iteration++;
-
-
-
/* d Dual
* Compute the value of ----------- (\lambda^k, \mu^k) this portion
* d \mu_i^k
* of code depends on function f(x).
*/
- bound_error = 0;
+ var_list = &(sys->variable_set);
xbt_swag_foreach(var1, var_list) {
-
mu_partial = 0;
-
- //for each link elem1 that uses flow of variable var1 do
- //mu_partial += elem1->weight + var1->bound;
-
- mu_partial = - (1 / mu_partial) + sum_bound;
+ if((var1->bound > 0) || (var1->weight <=0) ){
+ //for each link with capacity cnsts[i] that uses flow of variable var1 do
+ for(i=0; i<var1->cnsts_number; i++)
+ mu_partial += (var1->cnsts[i].constraint)->lambda;
+
+ mu_partial = -1.0 / mu_partial + var1->bound;
+ var1->new_mu = var1->mu - sigma_step * mu_partial;
- var1->bound = var1->bound + sigma_step * mu_partial;
+ if(var1->new_mu < 0){
+ var1->new_mu = 0;
+ }
+ }
}
-
-
- /*
- * Verify for each capacity constraint (lambda) the error associated.
+
+ /* d Dual
+ * Compute the value of ------------- (\lambda^k, \mu^k) this portion
+ * d \lambda_i^k
+ * of code depends on function f(x).
*/
+ j=0;
+ if(XBT_LOG_ISENABLED(surf_writelambda, xbt_log_priority_debug)) {
+ fprintf(gnuplot_file, "\n%d",iteration);
+ }
xbt_swag_foreach(cnst1, cnst_list) {
- cnst2 = xbt_swag_getNext(cnst1,(var_list)->offset);
- if(cnst2 != NULL){
- capacity_error += fabs(cnst1->value - cnsts2->value);
+ j++;
+
+ lambda_partial = 0;
+
+ elem_list = &(cnst1->element_set);
+ watch_out=0;
+ xbt_swag_foreach(elem1, elem_list) {
+
+ var2 = elem1->variable;
+
+ if(var2->weight<=0) continue;
+
+ tmp = 0;
+
+ for(i=0; i<var2->cnsts_number; i++){
+ tmp += (var2->cnsts[i].constraint)->lambda;
+ }
+ if(var2->bound > 0)
+ tmp += var2->mu;
+
+
+ if(tmp==0) break;
+
+ if (tmp==cnst1->lambda)
+ watch_out=1;
+ lambda_partial += (-1.0 / tmp);
}
+
+ if(tmp == 0)
+ cnst1->new_lambda = LAMBDA_STEP;
+ else {
+ lambda_partial += cnst1->bound;
+ if(watch_out && (lambda_partial>0)) {
+ /* INFO6("Watch Out (%d) %p! lambda_partial: %e; lambda : %e ; (%e %e) \n",iteration, cnst1, */
+ /* lambda_partial, cnst1->lambda, cnst1->lambda / 2, */
+ /* cnst1->lambda - sigma_step * lambda_partial); */
+
+ if(cnst1->lambda < 0) WARN2("Value of cnst1->lambda(%p) = %e < 0", cnst1, cnst1->lambda);
+ if((cnst1->lambda - sigma_step * lambda_partial) < 0) WARN1("Value of lambda_new = %e < 0", (cnst1->lambda - sigma_step * lambda_partial));
+
+ if(cnst1->lambda - sigma_step * lambda_partial < cnst1->lambda / 2)
+ cnst1->new_lambda = cnst1->lambda / 2;
+ else
+ cnst1->new_lambda = cnst1->lambda - sigma_step * lambda_partial;
+ } else
+ cnst1->new_lambda = cnst1->lambda - sigma_step * lambda_partial;
+ if(cnst1->new_lambda < 0){
+ cnst1->new_lambda = 0;
+ }
+ }
+
+ if(XBT_LOG_ISENABLED(surf_writelambda, xbt_log_priority_debug)) {
+ fprintf(gnuplot_file, " %e", cnst1->lambda);
+ }
+
}
+
/*
- * Verify for each variable the error of round trip time constraint (mu).
+ * Now computes the values of each variable (\rho) based on
+ * the values of \lambda and \mu.
*/
- bound_error = 0;
+ overall_error=0;
xbt_swag_foreach(var1, var_list) {
- var2 = xbt_swag_getNext(var1,(var_list)->offset);
- if(var2 != NULL){
- bound_error += fabs( var2->weight - var1->weight);
+ if(var1->weight <=0)
+ var1->value = 0.0;
+ else {
+ tmp = 0;
+ for(i=0; i<var1->cnsts_number; i++){
+ tmp += (var1->cnsts[i].constraint)->lambda;
+ if(var1->bound > 0)
+ tmp+=var1->mu;
+ }
+
+ //computes de overall_error
+ if(overall_error < fabs(var1->value - 1.0/tmp)){
+ overall_error = fabs(var1->value - 1.0/tmp);
+ }
+
+ var1->value = 1.0 / tmp;
}
+
+ }
+
+
+ /* Updating lambda's and mu's */
+ xbt_swag_foreach(var1, var_list)
+ if(!((var1->bound > 0.0) || (var1->weight <= 0.0)))
+ var1->mu = var1->new_mu;
+
+
+ xbt_swag_foreach(cnst1, cnst_list)
+ cnst1->lambda = cnst1->new_lambda;
+ }
+
+
+
+
+ //verify the KKT property
+ xbt_swag_foreach(cnst1, cnst_list){
+ tmp = 0;
+ elem_list = &(cnst1->element_set);
+ xbt_swag_foreach(elem1, elem_list) {
+ var1 = elem1->variable;
+ if(var1->weight<=0) continue;
+ tmp += var1->value;
+ }
+
+ tmp = tmp - cnst1->bound;
+
+
+ if(tmp != 0 || cnst1->lambda != 0){
+ WARN4("The link %s(%p) doesn't match the KKT property, value expected (=0) got (lambda=%e) (sum_rho=%e)", (char *)cnst1->id, cnst1, cnst1->lambda, tmp);
+ }
+
+ }
+
+
+ xbt_swag_foreach(var1, var_list){
+ if(var1->bound <= 0 || var1->weight <= 0) continue;
+ tmp = 0;
+ tmp = (var1->value - var1->bound);
+
+
+ if(tmp != 0 || var1->mu != 0){
+ WARN4("The flow %s(%p) doesn't match the KKT property, value expected (=0) got (lambda=%e) (sum_rho=%e)", (char *)var1->id, var1, var1->mu, tmp);
}
- overall_error = capacity_error + bound_error;
}
+
+
+
+ if(overall_error <= epsilon_min_error){
+ DEBUG1("The method converge in %d iterations.", iteration);
+ }else{
+ WARN1("Method reach %d iterations, which is the maxmimun number of iterations allowed.", iteration);
+ }
+
+
+ if(XBT_LOG_ISENABLED(surf_writelambda, xbt_log_priority_debug)) {
+ fclose(gnuplot_file);
+ }
+
+
+
+
+
+/* /\* */
+/* * Now computes the values of each variable (\rho) based on */
+/* * the values of \lambda and \mu. */
+/* *\/ */
+/* var_list = &(sys->variable_set); */
+/* xbt_swag_foreach(var1, var_list) { */
+/* tmp = 0; */
+/* for(i=0; i<var1->cnsts_number; i++){ */
+/* elem1 = &(var1->cnsts[i]); */
+/* tmp += (elem1->constraint)->lambda + var1->mu; */
+/* } */
+/* var1->weight = 1 / tmp; */
+
+/* DEBUG2("var1->weight (id=%s) : %e", (char *)var1->id, var1->weight); */
+/* } */
+
+
+
+
}
