From c7bae80f2d94af237ae36d12df714cff2d75b992 Mon Sep 17 00:00:00 2001
From: lempinen <lempinen@ac1ea38d-2e2b-0410-8846-a27921b304fc>
Date: Mon, 23 Aug 2010 12:19:29 +0000
Subject: [PATCH] Replaced interpolate function with a proper one

git-svn-id: https://www.simantics.org/svn/simantics/sysdyn/trunk@17470 ac1ea38d-2e2b-0410-8846-a27921b304fc
---
 .../sysdyn/modelica/ModelicaWriter.java       | 54 ++++++++++++++-----
 1 file changed, 40 insertions(+), 14 deletions(-)

diff --git a/org.simantics.sysdyn/src/org/simantics/sysdyn/modelica/ModelicaWriter.java b/org.simantics.sysdyn/src/org/simantics/sysdyn/modelica/ModelicaWriter.java
index 21aef064..7949b38d 100644
--- a/org.simantics.sysdyn/src/org/simantics/sysdyn/modelica/ModelicaWriter.java
+++ b/org.simantics.sysdyn/src/org/simantics/sysdyn/modelica/ModelicaWriter.java
@@ -41,20 +41,46 @@ public class ModelicaWriter {
             // THIS INTERPOLATE DOESN'T WORK PROPERLY
             b.append(
                     "\nfunction Interpolate\n" +
-                    "    input Real table[:, 2];\n" +
-                    "    input Real xp;\n" +
-                    "    output Real yp;\n" +
-                    "protected\n" +
-                    "    Integer i, sz;\n" +
-                    "algorithm\n" +
-                    "    sz := size(table,1);\n" +
-                    "    for i in 1:(sz-1) loop // assume monotonically increasing\n" +
-                    "    if ((i == 1 and xp <= table[i+1,1]) or\n" +
-                    "    (i == sz - 1) or\n" +
-                    "    (xp > table[i,1] and xp <= table[i+1,1])) then    // found appropriate segment\n" +
-                    "    yp := table[i,2] + (xp - table[i,1]) * (table[i+1,2] - table[i,2]) / (table[i+1,1] - table[i,1]);\n" +
-                    "    end if;\n" +
-                    "    end for;\n" +
+                    "	input Real u \"in1;put value (first column of table)\";\n" +
+                    "	input Real table[:, :] \"table to be interpolated\";\n" +
+                    "	input Integer icol \"column of table to be interpolated\";\n" +
+                    "	output Real y \"interpolated input value (icol column of table)\";\n" +
+                    "protected \n" +
+                    "	Integer i;\n" +
+                    "	Integer n \"number of rows of table\";\n" +
+                    "	Real u1;\n" +
+                    "	Real u2;\n" +
+                    "	Real y1;\n" +
+                    "	Real y2;\n" +
+                    "algorithm \n" +
+                    "	n := size(table, 1);\n" +
+                    "	if n <= 1 then\n" +
+                    "		y := table[1, icol];\n" +
+                    "	else\n" +
+                    "		// Search interval\n" +
+                    "		if u <= table[1, 1] then\n" +
+                    "			i := 1;\n" +
+                    "		else\n" +
+                    "			i := 2;\n" +
+                    "			while i < n and u > table[i, 1] loop\n" +
+                    "				i := i + 1;\n" +
+                    "			end while;\n" +
+                    "			i := i - 1;\n" +
+                    "		end if;\n" +
+                      
+                    "		// Get interpolation data\n" +
+                    "		u1 := table[i, 1];\n" +
+                    "		u2 := table[i + 1, 1];\n" +
+                    "		y1 := table[i, icol];\n" +
+                    "		y2 := table[i + 1, icol];\n" +
+                    "		// Interpolate\n" +
+                    "		if u1 >= u2 then\n" +
+                    "			y := y1;\n" +
+                    "			// since not possible to throw error\n" +
+                    "		else\n" +
+                    "			y := y1 + (y2 - y1)*(u - u1)/(u2 - u1);\n" +
+                    "		end if;\n" +
+                    "	end if;\n" +
             "end Interpolate;\n");
 
             b.append(
-- 
2.47.1