Buttons and Computations

  • Info - Brings up the information page.

  • Left Arrow - Scrolls the spreadsheet to the left.
  • Right Arrow - Scrolls the spreadsheet to the right.
  • Fill - Fills in zero entries for the blanks contained in the largest matrix determined by the nonzero entries.
  • Up Arrow - Scrolls the spreadsheet up.
  • Down Arrow - Scrolls the spreadsheet down.
  • Clear - Clears the spreadsheet.
  • Go - Performs the request to the left of the button.
  • Save As - Saves the matrix in the current spreadsheet after calling "Fill" (as described above). An error message will show if the matrix does not contain legal entries.
  • Display - Displays the selected matrix in the spreadsheet.
  • Inverse - Computes the inverse of the selected matrix (if it is nonsingular).
  • RREF - Computes the row reduced Echelon form of the selected matrix.
  • Det - Computes the determinant of the selected matrix.
  • Trace - Computes the sum of the diagonal entries of a nonempty matrix.
  • Transpose - Computes the transpose of the selected matrix.
  • EigVals - Computes the eigen values of the selected matrix and writes them in the log shown in the lower text area. Note that matrices with rational entries can have irrational eigen values.
  • EigVects - Computes the eigen values and the corresponding eigenvectors of the selected matrix, and writes the output to the log shown in the lower text area. The eigen values are listed first, followed by the eigenvector matrix. If the i-th eigen value is real, the i-th COLUMN of the eigenvector Matrix contains the corresponding eigenvector. If the i-th eigen value is complex with positive imaginary part, COLUMNS i and (i + 1) contain the real and imaginary parts of the corresponding eigenvector. The conjugate of this vector is the eigenvector for the conjugate eigen value. Note that matrices with rational entries can have irrational eigen values and eigen vectors.
  • Charpoly - Computes the characteristic polynomial of the selected matrix.  If the matrix is M, then charpoly returns det (M - z I).
  • RangeSpace - Returns a basis for the range space of the selected matrix by returning a matrix whose columns form a basis for the range space. If the selected matrix is the zero matrix, then the range space is trivial (only contains the zero vector).
  • NullSpace - Returns a basis for the null space of the selected matrix by returning a matrix whose columns form a basis for the null space. If the selected matrix is full rank, then the null space is trivial (only contains the zero vector).
  • Random m x n - Creates a random m by n matrix with integer values between -10 and 10.
  • Nice Random m x n - Creates an m by n matrix from the principle block of a square matrix with determinant 1 or -1 by creating a lower triangular matrix L with determinant +-1 and integer entries between -4 and 4, and an upper triangular matrix U with determinant +-1 and integer entries between -4 and 4, and then forming the product LU.
  • Multiplying a Scalar Times a Row - Multiplies the given scalar value by the selected row. The scalar must be a rational number.
  • Matrix Algebra - Combinations of matrices and the identity matrix can be computed using +, -, *, \, and augment provided the matrices are of appropriate size.
  • Row Swap - The selected rows will be interchanged.
  • Row Operations - A scalar times a row can be added to a scalar times another row and put in the position of the second row.
  • Add Comment - Adds a comment to the activity log shown in the lower text area.
  • Delete Row/Column - Deletes the selected row or column from the spreadsheet.
  • Clear Log - Clears the log of activity that is displayed in the lower text area.