Pseudocode:Loops and Vectorized code Comparison

$[$Execute this question in a new script named "Iname$\_$fname$\_$lab$4\_$comparison.m$"]$

Problem: Run the code given below. Investigate the time cost of two calculations:

a$)$ With uninitialized array

b$)$ With initialized array

c$)$ Write a comment about why it takes different amount of time.

$\%$ Iname$\_$fname lab$3$ comparison.m

: Compares tw$$ calc$$ulations with initialized and

uninitialized arrays.

clear; $\%$ Clear all variables

maxcount $=10$;$\%$ Number of repetitions

tic; $\%$ Start timer

for $jj=1$: maxcount

for ii $=1$:$10000$

square $(ii)=i{i}^{{?}^{{?}^{?}}}2$; Calculate square

end

end

toc; Ends timer and writes out the elapsed time

clear square; $\%$ Clear output array

tic; $\%$ Start timer

square $=$ zeros $(1,10000)$; Initialize the array

for $jj=1$ :maxcount

for $ii=1$:$10000$

square$($ii$)=$ ii$^2$; $\%$ Calculate square

end

end

toc; Ends timer and writes out the elapsed time

Background

tic: tic starts a stopwatch timer to measure performance. The function records the internal

time at execution of the tic command.

toc: Display the elapsed time with the toc function.

Example:

tic;

staments ; $.....$

toc;Introduction to Programming $-$ Lab Manual

Point Processing

$[$Execute this question in a new script named "Iname$\_$fname$\_$lab$4\_$p$\_$processing.m$"]$

Point processing is a linear or non$-$linear image manipulation method that is applied to

individual pixels.

Background

RGB $=$ imread$($filename$)$: The standard MATLAB function reads the image and loads it to

the workspace.

Problem:

a$)$ Take your selfie $($RGB domain$)$ and load image.

b$)$ Use "whos" function to learn about image size and RGB layer locations in the $n$

dimensional matrix. $(mxn3)$

c$)$ Implement your own code to apply below point filters.

d$)$ Use tic$-$toc function to log execution time of each filter.

e$)$ Comment on the results and execution time IN DETAIL.

STEP $-1$: Accumulate input data

Initialize $n$ to zero, initialize array numbers$\_$x to $0$ dimension array.

Prompt user for first positive number and note that "Entering $-1$ will end the process."

Read in first $x$

while $x0$

$$ nlarrn$+1$

${\displaystyle \underset{-}{\overset{?}{}}}x[n]=x$

Prompt user for next number

Read in next $x$

End

STEP $-2$: Calculate mean and Standard Deviation

$,x_{?}$bar larr sum$\_$x $/$ n

std$\_$dev larr sqrt$($ FILL IN THE BLANKS $)$

STEP$-3$: Write Out the results

Write out the mean value x$\_$bar

Write out the standard deviation std$\_$dev

Write out the number of input data points $n$

Additional Questions:

List the conditions when above program will fail.

How can you avoid these possible errors programmatically and change $"-1"$ exit flag to

any letter?