Merge pull request #53 from StaticBeagle/matrix-clean-up-updates

Matrix clean-up and updates

Author: staticbeagle

README.md

@@ -36,12 +36,12 @@ Maven
 <dependency>
     <groupId>com.wildbitsfoundry</groupId>
     <artifactId>etk4j</artifactId>
-    <version>2.2.1</version>
+    <version>2.2.2</version>
 </dependency>
 ```
 Gradle
 ```bash
-implementation 'com.wildbitsfoundry:etk4j:2.2.1'
+implementation 'com.wildbitsfoundry:etk4j:2.2.2'
 ```
 
 Requirements

pom.xml

@@ -2,7 +2,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.wildbitsfoundry</groupId>
     <artifactId>etk4j</artifactId>
-    <version>2.2.1</version>
+    <version>2.2.2</version>
     <name>Engineering Toolkit for Java</name>
     <description>Tools and implementation of mathematical methods or backing math for engineering problems and
         applications.

src/main/java/com/wildbitsfoundry/etk4j/math/linearalgebra/ComplexLUDecompositionDense.java

@@ -71,7 +71,7 @@ public ComplexLUDecompositionDense(ComplexMatrixDense matrix) {
 	@Override
 	public boolean isSingular() {
 		for (int j = 0; j < cols; ++j) {
-			if (_data[j * cols + j].equals(new Complex())) {
+			if (_data[j * cols + j].abs() == 0) {
 				return true;
 			}
 		}

src/main/java/com/wildbitsfoundry/etk4j/math/linearalgebra/LUDecompositionSparse.java

@@ -137,6 +137,9 @@ public MatrixSparse solve(double[] b) {
             int var10002 = b.length;
             throw new IllegalArgumentException("Unexpected number of rows in B based on shape of A. Found=" + var10002 + " Expected=" + this.rows);
         }
+        if (this.isSingular()) {
+            throw new RuntimeException("Matrix is singular.");
+        }
 
         double[] x = MatrixSparseUtils.adjust(this.gx, b.length);
         double[] rhs = MatrixSparseUtils.adjust(this.gb, b.length);
@@ -161,6 +164,10 @@ public MatrixSparse solve(MatrixSparse B) {
         if (B.getRowCount() != this.rows) {
             throw new IllegalArgumentException("Matrix row dimensions must agree.");
         }
+        if (this.isSingular()) {
+            throw new RuntimeException("Matrix is singular.");
+        }
+
         MatrixSparse X = new MatrixSparse(0, 0, 0);
         X.reshape(cols, B.cols, X.rows);
 

src/main/java/com/wildbitsfoundry/etk4j/math/linearalgebra/MatrixDense.java

@@ -1030,7 +1030,7 @@ public String toString() {
             if (i > 0 && i % cols == 0) {
                 sb.append(System.lineSeparator());
             }
-            sb.append(String.format("%.4g", data[i])).append(" ");
+            sb.append(String.format("%-10.4g", data[i])).append(" ");
         }
         sb.setLength(sb.length() - 1);
         return sb.toString();

src/main/java/com/wildbitsfoundry/etk4j/math/linearalgebra/MatrixSparse.java

@@ -478,30 +478,19 @@ public static MatrixSparse from2DArray(double[][] array) {
     }
 
     public static MatrixSparse from2DArray(double[][] array, double tol) {
-        int nonzero = 0;
-        for (int i = 0; i != array.length; i++)
-            for (int j = 0; j != array[i].length; j++) {
-                if (array[i][j] != 0) {
-                    nonzero++;
-                }
-            }
-        MatrixSparse dst = new MatrixSparse(array.length, array.length, nonzero);
-        dst.nz_length = 0;
-        dst.col_idx[0] = 0;
-        int i, j;
-        for (i = 0; i != array[0].length; i++) {
-            for (j = 0; j != array.length; j++) {
-                double value = array[j][i];
-                if (Math.abs(value) > tol) {
-                    dst.nz_rows[dst.nz_length] = j;
-                    dst.nz_values[dst.nz_length] = value;
-                    ++dst.nz_length;
+        int rows = array.length;
+        int cols = array[0].length;
+
+        MatrixSparse matrixSparse = new MatrixSparse(rows, cols);
+
+        for(int i = 0; i < rows; i++) {
+            for(int j = 0; j < cols; j++) {
+                if(Math.abs(array[i][j]) > tol) {
+                    matrixSparse.unsafeSet(i, j, array[i][j]);
                 }
             }
-            dst.col_idx[i + 1] = dst.nz_length;
         }
-
-        return dst;
+        return matrixSparse;
     }
 
     /**
@@ -827,6 +816,13 @@ public MatrixDense toDense() {
         return matrixDense;
     }
 
+    @Override
+    public String toString() {
+        return toDense().toString()
+                .replaceAll(" {6}0.000 {6}", "                 ")
+                .replaceAll("0.000 {6}", "           ");
+    }
+
     public static class Factory {
         private Factory() {}