diff -rupN --no-dereference ncl-6.6.2/ni/src/lib/nfp/TransformCoordinate.c ncl-6.6.2-new/ni/src/lib/nfp/TransformCoordinate.c
--- ncl-6.6.2/ni/src/lib/nfp/TransformCoordinate.c	2019-02-28 00:44:39.000000000 +0100
+++ ncl-6.6.2-new/ni/src/lib/nfp/TransformCoordinate.c	2021-03-10 19:16:04.100897315 +0100
@@ -1,48 +1,39 @@
 #include <stdio.h>
-#include <proj_api.h>
+#include <proj.h>
 #include "TransformCoordinate.h"
 
 int TransformCoordinate(char * SrcProjStr, char * DstProjStr,
         double * x, double * y, double * z,
         unsigned int nPoint) {
-    projPJ SrcProj, DstProj;
+    PJ *proj;
     int Err, i;
+    PJ_COORD* c = (PJ_COORD*)malloc(nPoint * sizeof(PJ_COORD));
 
     /* Constructing the projections */
-    if (!(SrcProj = pj_init_plus(SrcProjStr))) {
-        printf("FATAL ERROR: Can not make a projection out of <%s>\n", SrcProjStr);
+    if (!(proj = proj_create_crs_to_crs(PJ_DEFAULT_CTX, SrcProjStr, DstProjStr, NULL))) {
+        printf("FATAL ERROR: Can not create transform from <%s> to <%s>\n", SrcProjStr, DstProjStr);
         return (1);
     }
-    if (!(DstProj = pj_init_plus(DstProjStr))) {
-        printf("FATAL ERROR: Can not make a projection out of <%s>\n", DstProjStr);
-        return (2);
-    }
 
-    /* Converting to radian if needed */
-    if (pj_is_latlong(SrcProj)) {
-        for (i = 0; i < nPoint; i++) {
-            x[i] *= DEG_TO_RAD;
-            y[i] *= DEG_TO_RAD;
-        }
+    for (i = 0; i < nPoint; ++i) {
+        c[i].xyz.x = x[i];
+        c[i].xyz.y = y[i];
+        c[i].xyz.z = z[i];
     }
 
     /* Transforming the coordinates */
-    if ((Err = pj_transform(SrcProj, DstProj, nPoint, 1, x, y, z)) != 0) {
-        printf("FATAL ERROR: %s\n", pj_strerrno(Err));
-        return (3);
-    }
+    proj_trans_array(proj, PJ_FWD, nPoint, c);
 
-    /* converting to degree if needed */
-    if (pj_is_latlong(DstProj)) {
-        for (i = 0; i < nPoint; i++) {
-            x[i] *= RAD_TO_DEG;
-            y[i] *= RAD_TO_DEG;
-        }
+    for (i = 0; i < nPoint; ++i) {
+        x[i] = c[i].xyz.x;
+        y[i] = c[i].xyz.y;
+        z[i] = c[i].xyz.z;
     }
 
     /* freeing the projection */
-    pj_free(DstProj);
-    pj_free(SrcProj);
+    proj_destroy(proj);
+    free(c);
+
     return (0);
 }