1 files changed, 131 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/pqc/math/linearalgebra/Matrix.java b/core/src/main/java/org/spongycastle/pqc/math/linearalgebra/Matrix.java
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+++ b/core/src/main/java/org/spongycastle/pqc/math/linearalgebra/Matrix.java
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+package org.spongycastle.pqc.math.linearalgebra;
+
+/**
+ * This abstract class defines matrices. It holds the number of rows and the
+ * number of columns of the matrix and defines some basic methods.
+ */
+public abstract class Matrix
+{
+
+    /**
+     * number of rows
+     */
+    protected int numRows;
+
+    /**
+     * number of columns
+     */
+    protected int numColumns;
+
+    // ----------------------------------------------------
+    // some constants (matrix types)
+    // ----------------------------------------------------
+
+    /**
+     * zero matrix
+     */
+    public static final char MATRIX_TYPE_ZERO = 'Z';
+
+    /**
+     * unit matrix
+     */
+    public static final char MATRIX_TYPE_UNIT = 'I';
+
+    /**
+     * random lower triangular matrix
+     */
+    public static final char MATRIX_TYPE_RANDOM_LT = 'L';
+
+    /**
+     * random upper triangular matrix
+     */
+    public static final char MATRIX_TYPE_RANDOM_UT = 'U';
+
+    /**
+     * random regular matrix
+     */
+    public static final char MATRIX_TYPE_RANDOM_REGULAR = 'R';
+
+    // ----------------------------------------------------
+    // getters
+    // ----------------------------------------------------
+
+    /**
+     * @return the number of rows in the matrix
+     */
+    public int getNumRows()
+    {
+        return numRows;
+    }
+
+    /**
+     * @return the number of columns in the binary matrix
+     */
+    public int getNumColumns()
+    {
+        return numColumns;
+    }
+
+    /**
+     * @return the encoded matrix, i.e., this matrix in byte array form.
+     */
+    public abstract byte[] getEncoded();
+
+    // ----------------------------------------------------
+    // arithmetic
+    // ----------------------------------------------------
+
+    /**
+     * Compute the inverse of this matrix.
+     *
+     * @return the inverse of this matrix (newly created).
+     */
+    public abstract Matrix computeInverse();
+
+    /**
+     * Check if this is the zero matrix (i.e., all entries are zero).
+     *
+     * @return <tt>true</tt> if this is the zero matrix
+     */
+    public abstract boolean isZero();
+
+    /**
+     * Compute the product of this matrix and another matrix.
+     *
+     * @param a the other matrix
+     * @return <tt>this * a</tt> (newly created)
+     */
+    public abstract Matrix rightMultiply(Matrix a);
+
+    /**
+     * Compute the product of this matrix and a permutation.
+     *
+     * @param p the permutation
+     * @return <tt>this * p</tt> (newly created)
+     */
+    public abstract Matrix rightMultiply(Permutation p);
+
+    /**
+     * Compute the product of a vector and this matrix. If the length of the
+     * vector is greater than the number of rows of this matrix, the matrix is
+     * multiplied by each m-bit part of the vector.
+     *
+     * @param vector a vector
+     * @return <tt>vector * this</tt> (newly created)
+     */
+    public abstract Vector leftMultiply(Vector vector);
+
+    /**
+     * Compute the product of this matrix and a vector.
+     *
+     * @param vector a vector
+     * @return <tt>this * vector</tt> (newly created)
+     */
+    public abstract Vector rightMultiply(Vector vector);
+
+    /**
+     * @return a human readable form of the matrix.
+     */
+    public abstract String toString();
+
+}