Tag Archives: matrix

Visualizing TensorFlow with TensorBoard

TensorBoard is a tool for visualizing graphs and various metrics for TensorFlow session runs. With a few line of additional code, TensorBoard gathers and report run statistics in a nice graphical interface.tensorboard1

First of all a few lines are required to TensorFlow session as in below:

writer = tf.summary.FileWriter("output", sess.graph)
print(sess.run(GH, options=options, run_metadata=run_metadata))
writer.close()

Before running the session, start TensorBoard using the following command.
tensorboard2

Finally run the TensorFlow session and point the browser to the TensorBoard.
tensorboard3

Advertisements

Hessian matrix in Nspire

The Hessian is a matrix composed of second order partial derivatives of function. The Nspire does not provide built-in function for this, and a handy function below achieve the same purpose, although it is good for a 2 x 2 matrix.
hessian1

The HP Prime provided built-in function for Hessian matrix.
hessian2

Doing matrix multiplication in TI Nspire and Excel

In TI Nspire, matrix multiplication can be accomplished in the Calculator page. The process is intuitive and easy with the visual templates.

Firstly use the matrix template to define one:
matrixnspire1matrixnspire2

Then simply do multiplication after filling in the matrix elements.
matrixnspire4

Doing so in Excel required the use of the MMULT() function. A little trick is needed for this function for returning answer in array format – by pressing CTRL+SHIFT+ENTER at the same time after inputting the function for the cells selected as output array.

First step, fill in the matrix with the elements into respective cells.
matrixexcel1

Mark the output region to use the array function. In this example it is also a 3×3 matrix.
matrixexcel2

Apply the MMULT() function on the upper left corner cell of the region selected.
matrixexcel3

The trick is here, when finished typing in the function, press CTRL+SHIFT+ENTER instead of just ENTER. The answer from the function will then be populated in the selected cells, and the formula will be displayed with curly brackets enclosed, like  {=MMULT(B2:D4,F2:H4)}.matrixexcel4

Simplex Algorithm on the Casio 9860GII

With matrix capable calculator, simplex algorithm for common maximization problem can be solved easily like in the TI-84.

The Casio 9860GII is also equipped with equivalent matrix operations to solve the same problem.

casiosimplex1

casiosimplex2

casiosimplex4

casiosimplex3