comparison toolboxes/distance_learning/mlr/util/cummax.c @ 0:e9a9cd732c1e tip

first hg version after svn

+/* CREATED:2010-01-08 17:25:37 by Brian McFee <[e-mail]> */
+/* cummax.c
+ *
+ *  cumulative maximum (analogous to cumsum)
+ *
+ * Compile: 
+ *  mex cummax.c
+ */
+
+#include "mex.h"
+
+void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
+{
+    /* Declare variables */
+    int n;      /* number of elements */
+    double *pi; /* input array */
+    double *po1, *po2; /* output array(s) */
+    double currentMax;
+    double currentMaxPointer;
+    int i;
+
+    if (nrhs != 1) {
+        mexErrMsgTxt("Only one input argument is required.");
+    }
+    if (nlhs > 2) {
+        mexErrMsgTxt("Too many output arguments.");
+    }
+
+    if (!(mxIsDouble(prhs[0]))) {
+        mexErrMsgTxt("Input array must be of type double.");
+    }
+
+    n       = mxGetNumberOfElements(prhs[0]);
+    pi      = (double *)mxGetPr(prhs[0]);
+    
+    plhs[0] = mxCreateDoubleMatrix(1, n, mxREAL);
+    po1     = mxGetPr(plhs[0]);
+
+    plhs[1] = mxCreateDoubleMatrix(1, n, mxREAL);
+    po2     = mxGetPr(plhs[1]);
+
+    /* Now for the meat */
+
+    currentMax = pi[0];
+    currentMaxPointer = 1;
+    for (i = 0; i < n; i++) {
+        if (pi[i] > currentMax) {
+            currentMax          = pi[i];
+            currentMaxPointer   = i + 1;
+        }
+        po1[i] = currentMax;
+        po2[i] = currentMaxPointer;
+    }
+
+    mxSetN(plhs[0], n);
+    mxSetN(plhs[1], n);
+
+}