Python Homework (.csv files images, creating graphs)

Hurricane.csv files.

There are multiple csv files for different named hurricanes. (The atlantic-basin.csv file is not a storm file, but contains region information about the map. More about that later.). Each line in the storm csv file contains information about the storm at a particular point and time. The first 4 lines of irma.csv appear in below

Date,Time,Lat,Lon,Wind,Pressure

Aug 30,15:00 GMT,16.4,-30.3,50,1004

Aug 30,21:00 GMT,16.4,-31.2,60,1001

Aug 31,03:00 GMT,16.4,-32.2,65,999

The first line only tells us what the columns are, we will always assume the columns are in the same order. After that line we get information about date, time lat, lon, wind and pressure. We will only be concerned with lat, lon and wind speed.

At each line we’ll want to mark the hurricane on the map with the latitude, longitude line weight and color to draw the line. The Line weight and color are determined by the category of the storm. Hurricane categories go from 0 to 5. The line weight should be proportional to the category. You can decide on how much weight to give it. The color by category is given below.

windowUtil module

The window util module will help you create the graphic window and display the map and hurricane data. As long as the solution is in the same directory, you can simply import the module like any other.

import windowUtil

Creating a window

To create a new window we must create a WindowUtil instance and initialize it. It takes 4 arguments, the name of the window, the width, the height and the name of the image file to use for the background.

win = windowUtil.Window("Hurricane Data", 1000, 900, img="atlantic-basin.png")

You’ll notice that this creates a window slightly larger than our image. (We’ll use the atlantic-basin.csv image for data about the image size as well as the lat and longitude boundaries)

The win variable above is an instance of the class that handles our window. We use it to call methods to plot the hurricane and update the screen.

Setting the map boundaries

After we’ve created our window, we need to tell it where the boundaries are for the lat and long, so that it can translate them onto the map. The set range method takes 4 arguments, lat1, lat2, long1, and long2.

win.set_range(0, 45, -90, -17.66)

This tells it that the lowest latitude is 0 and the highest latitude shown is 45. The left hand side longitude is -90 degrees and the right hand side longitude is -17.66 degrees.

Plotting the hurricane

The plot_hurricane method takes 4 arguments, the lat, long, linewidth, and color of the hurricane at that point. After we plot the hurricane we need to refresh the screen and we can do so with the update method. This method takes no arguments.

win.plot_hurricane(16.4, -30.3, 2, "blue")

win.update()

You’ll notice it plots the hurricane graphic on our screen. The image of the hurricane isn’t blue, but if there was a line drawn up to that point it would be blue. Now try another spot, just a little farther away.

win.plot_hurricane(18, -50, 5, "red")

win.update()

If the window isn’t available because the user closed it, then win.update() will throw an exception the exception is windowUtil.WindowCloseError

The hurricane isn’t positioned correctly on this map simply because our map didn’t cover the entire size of the window. Changing the window size to 945, 600 will alleviate that.

That’s all you will need in order to create a window and plot the hurricane. Pretty easy.

atlantic-basin.csv

This csv contains information about how the .png file should be displayed. The first line is the width and the high. In this case 945x600.

The next line contains lat1, lat2, long1, and long2. These are the latitude and longitude boundaries for the given map. You should not hard code these into your program. The grader may use a different map and different values to test your solution.

The csv module is very useful for reading through csv files. You don’t have to use it, but you may find it easier than the .split() method. You open and close a file as you normally would, but then pass the file handle to the reader function. This returns a csv handle that you can iterate over. It will automatically read each line is a list that has been split on the commas.

import csv

fh = open("irma.csv")

fh_csv = csv.reader(fh)

for line in fh_csv:

print(line)

fh.close()

time Module

After each call to update you should let python sleep for a fraction of a second. Otherwise it will draw the map too quickly and you won’t see the process of it drawing. Just import time module at the top of the program and call time.sleep(0.2) This puts the python thread to sleep for 2 tenths of a second, letting the user see and enjoy your map as it gets drawn.

Requirements

· Display the hurricane at each lat and longitude from the input file. You’ll need to convert the lat, long and windspeed into floats. Some files may have bad data, and you should catch the ValueError if they cannot be converted and show the user a nice error message and then go to the next line. Some lines also might not contain the correct number of columns, so an IndexError may occur. You should respond to those as well.

· Once the hurricane has been mapped you should continue to update the map so that the hurricane icon animates and wait for the user to close the window.

· Once the window is closed ask the user to display another hurricane image as shown in the example

Development notes.

· Don’t try to write it all at once, take your time and work on one skill at a time.

Enter the name of the hurricane file (quit to exit) ==> badfile

Could not open the file, please enter another.

Enter the name of the hurricane file (quit to exit) ==> badindex.csv

Index error, line did not contain all columns ['Aug 30', '']

Thanks for viewing!

Enter the name of the hurricane file (quit to exit) ==> badvalue.csv

Could not convert value to float ['Aug 30', '21:00 GMT', 'Three', '-31.2', '60', '1001']

Thanks for viewing!

Enter the name of the hurricane file (quit to exit) ==> irma.csv

Thanks for viewing!

Enter the name of the hurricane file (quit to exit) ==> Quit