MATLAB TEST 1
Plot type: experimental data, mathematical phenomena, relationship among different data sets.
scatter plot
a file that contains a set of commands that perform a particular function. Saved with a ".m"
script
you CANNOT run a ___________ ________ if a variable has not been previously defined in the command window.
self-defined function
if time= [1.9 2.9 3.8 4.6 5.5 6.3 7.1] distance= 10:10:100 and: average_speed= distance/time what is the result? a ____ value [WE DONT WANT THIS] what do we have to use to correct this: use the ____ _____ which gives us speed at each time point
single/dot operator
in E= linspace(1,10,4) 1 is the _____ point 10 is the ____ value 4 is the ______ __ _____
starting/final/number of values
in the vector F= 0:2:10 0 is the _____ point 2 is the __________ 10 is the ____ _____
starting/increment/final value
the result of fprintf is written as a _________
string
write a command that loads the string name heya.txt variable name: student
student= 'heya.txt' load(student)
write a command that imports: heya.txt and assign it to the variable student
student= load('heya.txt')
Plot commands: Use this command to plot multiple data sets in the same figure but on separate axis
subplot(row, column, plot location/#)
time= [1.9 2.9 3.8 4.6 5.5 ] type up a command that will give me the third time value
time(3)
Format plot: give the plot title: Heya is amazing xlablel: classes ylabel: heya's brain cells turn on grid
title('Heya is amazing') xlabel('classes') ylabel('Heya's brain cells') grid on
flip data from row to column
transpose
true or false: variables used in one execution of one script will be carried over into the next script.
true
a one-dimensional array; composed of a single row or column of entries ex. [1,2,3,4,5,6]
vector
what does the command find sin(pi/2) do: prints a ______
vector
5 ways to get help on Matlab
website f(x) button help help command doc command
a command that gives you information about the variables defined in the work place. This command gives you the name of the variable, its size, bytes, class, and attributes
whos
above the command history: where the variables x and y are contained
workspace
scripts can access variables created in the _________
workspace
draw a log(x) graph using a colon domain of 1-10 use a star marker
x= 1:10; y= log(x) plot(x,y,'*')
create a column vector of 1-5 without commas or spaces define the vector as x
x= 1:5
Create a column vector of 1-5 without commas or colons define the vector as x
x= [1 2 3 4 5]
create a column vector of 1-5 without colons or empty spaces define the vector as x
x= [1,2,3,4,5]
find x^3 using matlab
x^3
the most basic array; contains only one entry ex. 5
scalar
fprintf the ______ tells MATLAB to insert the value of the variable after the comma as a fixed-point value with two decimal places.
%.2f
"___" tells Matlab to insert the value of the variable after the commas as a whole number
%d
fprintf %s _____ \n ______ %d ____ %f _____
%s = replacing a variable in a string with a variable name \n = enters a string one line down %d= insert number as a whole number %f= specify decimal places of a number to be printed
three different file types:
.csv .txt .dat
csvread is ____ indexed.
0
matlab starts counting at __ instead of ___. That's why the csvread command is 1,0 as row 1 column 0 when in reality it is row 2 and column 1.
0/1
fprintf the %.2f tells MATLAB to insert the value of the variable after the comma as a fixed-point value with ____ decimal places. EXAMPLE: >> temperature= 100.98405830432 temperature = 100.9841 >> fprintf('Hello it"s me, i"ve been waiting outside in this %.2f degree weather',temperature) Hello it"s me, i"ve been waiting outside in this 100.98 degree weather>>
2
In the matrix below, the rows are separated by: ____ A= [2 4; 6 8; 10 12]
;
negation of 1
>> -1
division of 15/3
>>15/3
multiplication of 3 x 3
>>3*3
add 3 +3
>>3+3
subtract 3-3
>>3-3
exponentiation of 3 to 2 power
>>3^2
Create Matrix "A" with values 2,4 in the first row 6,8 in the second row and 10,12 in the third row
A= [2 4; 6 8; 10 12]
write the command that transposes this column vector to a row vector B= [1 2 3 4 5]
B= [1 2 3 4 5]'
Use a command to make a vector that goes from 1-10 but only uses 4 values. Call this vector "E."
E= linspace(1,10,4)
Make a column vector of values from 1-10. Take a short cut so they are separated by increments of 2. Define vector as F.
F= 0:2:10
type the output: >>fprintf('Hello there')
Hello there
type the output: fprintf('Hello there\n')
Hello there (entered down a line)
type the output: name= Robert >>fprintf('Hello there, my names"s %s\n', name)
Hello there, my name's Robert (entered down a line)
What is the output: rabbits = 10 >> fprintf('Luna is a straight up %d',rabbits)
Luna is a straight up 10.
order of operations
Please Excuse Tinder Not My Dear Aunt Sally cuz P-parenthesis () E-exponentiation ^ T- transpose ' N - negation (-) M- multiplication(*) D- division(/) A- addition(+) S- subtraction (-) C- comparison (=, =< , >=, <, >)
if matrix1= [1 2; 3 4] and matrix2= [10 20; 30 40] and matrix3= matrix1.*matrix2 what does matrix 3=
[10 40; 90 160]
fprintf statement: "___" adds a line break
\n
Make three different vectors of 1-5 define them as a, b, c a -> use no spaces b -> use commas c -> use a colon
a= [1 2 3 4 5] b= [1,2,3,4,5] c= 1:5
find theta if the opposite side is 3, and the hypotneuse is 5
arcsin((3/5)*pi/180)
the fundamental form Matlab uses to store and manipulate data. It is a list of data entries arranged into rows and or columns
array
in the ______section: perform calculations and manipulate inputs
calculations
a command that will clear all data
clear
a command that will clear the variable yellow
clear yellow
format of a csv formated file
comma seperated (comma separates the fields of text)
a sequence of values, functions, or operators that performs a calculation or other function
command
the command you use to load a .csv file
csvread
the two commands used to load data:
csvread load
write a command that loads the string collegesucks.csv
csvread('collegesucks.csv')
write a command that loads a string skipping the fist row collegesucks.csv
csvread('collegesucks.csv',1,0)
format of a dat formated file
data (can include data, text, graphics)
format of a txt formatted file
delimited text (tabs separate each fields of text)
how to get a document that shows you information about the cosine function
doc cos
When working with matrices and want to use multiplication we use the ____ operator
dot
type the output: fprintf('Hello there, my name"s Robert\n') **notice how for name's in fprintf you must use "
ello there, my name's Robert (entered down a line)
write a command that loads the string name collegesucks.csv variable name= engineering
engineering= 'collegesucks.csv' load(engineering)
import data from file called: lifesucks.csv call it engineeringmajor import the x-values and call it homeworkhours which is in column 1 import the y-values and call it number of sleep hours which is in column 2 create a histogram with 8 bins format correctly with labels, etc.
engineeringmajor= csvread('lifesucks.csv') homeworkhours(:,1); sleephours(:,2) hist(sleephours,8) title('Histogram of Hours of Sleep') xlabel('hours of homework') ylabel('hours of sleep') grid on
Plot commands: used not to replace previous plot, and allows us to create a new plot
figure
windows created by plotting commands are
figures
To execute a script press ____ OR go to the command window and type the script name WITHOUT _____ and press enter.
run/.m
a command that can save a file called mydata
save mydata
given: name= 'Heya' (you need to put it in 'quotes' or it will not work) testaverage1= 65 testaverage2=54 testaverage3= 84 write a command that prints: use variable references and fprintf commands, make the score print with 3 decimal points. Hello there, my name's Heya and my test average is 67%.
fprinft('Hello there my name"s %s and my test average is %.3f.', name, (testaverage1+testaverage2+testaverage3/3))
print to screen command
fprintf
how to get help with a description printed directly on the screen for the sin function.
help sin
Plot commands: This command toggles whether existing data in a figure should be erased (done by matlab not explicitly by you)
hold
Plot commands: matlab will continue to plot on the same axis until this command is executed
hold off
Plot commands: allows us to continue to plot, plots more equations and data
hold on
in the _____ section: assign constants or variables, import data, or receive input from the user
inputs
write command: find the number of elements in the LONGEST dimension of the array: x=[1,2,3,4,5,6]
length(x)
variable name rules 1) Must start with a ________. 2)Must contain _____, ______, or _________. 3) Are ______ sensitive. 4)Must not be a Matlab __________ 5) Do not use __________ function names.
letter/letter/number/underscore/case/keyword/built-in function
Plot type: evenly spaced or sample data, time-series data taken at even intervals, displays categorical data
line plot
the command you use load a .txt file
load
the command you use to load a .dat file
load
load the variable pink in workspace
load pink
command that will load saved data, the file's name is mydata
load('mydata.mat')
write a command that will give you the ln of 10
log(10)
write a command that will give you the log of 10
log10(10)
a 2D-array; collection of entries arranged into rows and columns ex. [1,2 ; 3,4]
matrix
multiply "matrix1" and "matrix2" together using the dot operator to make "matrix4"
matrix4= matrix1.*matrix2
write command: find the maximum value of x= [1,2,3,4,5,6]
max(x)
command that finds the average of the numbers: 1,2,3,4,5
mean([1 2 3 4 5])
write command: find the minimum value of x= [1,2,3,4,5,6]
min(x)
the commands csvread and load only work on _________ data
numerical
in the ________ section: supply the final output
outputs
Plot commands: write command to plot x and y
plot(x,y)
write command: find the range of: x= [1,2,3,4,5,6]
range= max(x) -min(x)
in the _______ section: paste results and answer questions
results
