General Computer Science for Engineers CISC 106 Lecture 05 James Atlas Computer and Information Sciences 6/22/2009

Lecture Overview Review Plotting Simple Plots Arrays Recursion

Review For loop If statement

Branching Constructs We already covered the IF statement Why would IF be considered a “branch”?

Branching Constructs Why would IF be considered a “branch”? ◦ Let’s look at what happens to our code when it is executing on the CPU

Switch construct switch (switch_expression) case case_expr_1 statement 1 statement 2 case case_expr_2 statement 1 statement 2 otherwise statement 1 statement 2 end

Switch construct color = ‘yellow’; switch (color) case ‘red’ disp(‘Stop now!’); case ‘green’ disp(‘Proceed through intersection.’); case ‘yellow’ disp(‘Prepare to stop.’); otherwise disp(‘Illegal color encountered.’); end

For loop for sum integers total = 0; for i = 1:1:100 loop starts at 1 total = total+i; loop increments by 1 end

While loop while expression statement end

While loop for sum integers total = 0; i = 1; while i <= 100 loop starts at 1 total = total+i; loop increments by 1 i = i + 1; end

Recursion

Plot Using the plot command plot(, ) where array1 is the x-axis and array2 is the y-axis NOTE: array1 and array2 must be equal in terms of size of dimensions!

Plot For example: x=[ ]; y=[ ]; plot(x,y)

Plot Other useful command with plot xlabel(‘ ’) – sets the label for the x-axis ylabel(‘ ’) – sets the label for the y-axis grid on – creates a grid title(‘ ’) – sets title of the plot

Plot For example: x=0:1:10; y=x.^ *x + 15; plot(x,y)

Plot commands title(‘Graph Title’); xlabel(‘X axis label’); ylabel(‘Y axis label’); grid on; legend(‘series 1’, ‘series 2’,..., ‘BR’); print -dpng mygraph.png