Graphing

=Making Graphs= Graphs and charts are great because they communicate information visually. For this reason, graphs are often used in newspapers, magazines and businesses around the world.

How to Choose Which Type of Graph to Use?
Line graphs are used to track changes over short and long periods of time. When smaller changes exist, line graphs are better to use than bar graphs. Line graphs can also be used to compare changes over the same period of time for more than one group.
 * Line graph.**

Pie charts are best to use when you are trying to compare parts of a whole. They do not show changes over time.
 * Pie Chart.**

Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger.
 * Bar Graph or Histogram.**

X-Y plots are used to determine relationships between the two different things. The x-axis is used to measure one event (or variable) and the y-axis is used to measure the other. If both variables increase at the same time, they have a positive relationship. If one variable decreases while the other increases, they have a negative relationship. Sometimes the variables don't follow any pattern and have no relationship.
 * X-Y Plot.**

=Line Graphs= Line graphs can be used to show how something changes over time. Line graphs are good for plotting data that has peaks (ups) and valleys (downs), or that was collected in a short time period. = = The title offers a short explanation of what is in your graph. This helps the reader identify what they are about to look at.
 * The Title**

The legend tells what each line represents. Just like on a map, the legend helps the reader understand what they are looking at.
 * The Legend**

In line graphs, the y-axis runs vertically (up and down). Typically, the y-axis has numbers for the amount of stuff being measured. The y-axis usually starts counting at 0 and can be divided into as many equal parts as you want to.
 * Y-Axis**

The most important part of your graph is the information, or data, it contains. Line graphs can present more than one group of data at a time. In this graph, two sets of data are presented.
 * The Data**

In line graphs, like the one above, the x-axis runs horizontally (flat). Typically, the x-axis has numbers representing different time periods or names of things being compared. In this line graph, the x-axis measured different school years.
 * X-Axis**

=Basic Histogram Graphs= Ref: http://passyworldofmathematics.wordpress.com/2012/03/04/basic-histogram-graphs/



Image Source: http://passmath.co.uk In this lesson we will be looking at how to make a type of statistics graph called a “Histogram”.

Drawing a Basic Histogram Video media type="youtube" key="KCH_ZDygrm4?feature=player_embedded" height="360" width="640"

Making a Frequency Table

Often in graphing and in particular statisitcs we use a Frequency Table which shows data. For instance the number of drunk drivers in a week.

This information can be represented on a graph. The following video explains how to make a frequency table.



media type="youtube" key="ipZzfE3Nk1I?feature=player_embedded" height="360" width="640"

Once we have our data we can make our histogram:

The first step we need to do for our Histogram graph is work out what units the scale along the vertical axis is going to be done in: ones, twos, fives, tens, etc.


 * Step 1: Set up your bottom (X) axis **

First, we need to figure out the total range of values represented by all the data: In this case the number of days.

This axis represents number of drunk drivers.The least was 3 and the most 22. So we need to have a range from 3 to 22. We need to determine the values to be represented. In this case the easiest is to have intervals of 2. So the vertical axis will begin at 0 and end at 22 going up in units of 2.
 * Step 2: Set up your side (y) axis **

The next step is to set up the horizontal axis, and the vertical axis for our graph. We can now Draw and Label each axis and add the Title at the top of our Histogram.

Note that it is not necessary to colour in all of the bars different colours.
 * Step 3: Make the data bars & title **

** Some important graphing tips: **
 * Step 4: Label the axis and do a title. **

 * Whatever value you decide to make each line, be consistent throughout, and go in numerical order from lowest to highest value. For instance if you have data values between -0.14 and +0.09, make sure you have lines for all the numbers in between, and in their proper order and spacing. If you aren’t sure how to do this, ask your nice teacher for some assistance. It will save you some embarrassment, and make your teacher feel important.

* Use a ruler to make your lines nice and straight. It will dazzle your nice teacher and make your classmates envy your professional-looking histograms.

 * Make sure you label all axes of your graph, including units. If you forget to label your graphs frequently, your nice teacher might not be so nice anymore.

Making Histograms Using MS Excel

The following Slideshare document shows how to make a Histogram in MS Excel.

Use the up and down arrow icons to move down through the document.

Make the document full screen by clicking on the bottom right hand icon. This will make it possible to read the screen prints clearly.media type="custom" key="12863790"

[|Slideshare]

=Pie Graphs= Pie charts can be used to show percentages of a whole, and represents percentages at a set point in time. Unlike bar graphs and line graphs, pie charts do not show changes over time. The most important part of your chart is the information, or data, it contains. Pie charts represent data as part of 100 (a percentage). Each slice represents a different piece of data. The following video provides an overview on pie graphs. media type="youtube" key="y3EEoI5wngE" height="315" width="420"
 * The Data**

=Step 1: First select how many slices your pie chart will have= How many sections do you want to make in your Pie Chart? How many categories you want to create in the pie chart you're going to make.

=Step 2: Determine how to represent your legend= This pie chart has the legend on the side



Image Source: Graphjam.com

This pie chart has the legend next to the slices source: http://chartmaker.mathwarehouse.com/create-pie-chart/

Split Pie Chart
> You can create split pie charts (for both 2 dimensional and 3 dimensional charts) || **3 Dimensional Split Pie Chart** || source: http://chartmaker.mathwarehouse.com/create-pie-chart/ =Internet Resources=
 * **2 Dimensional Split Pie Chart**

Microsoft Excel is great for making Charts and Graphs. However we can also use some free Graph makers on the Internet for doing most of the basic graphs we need for mathematics.

Two good free online graph makers are: “Kids Zone Make a Graph” at:

@http://nces.ed.gov/nceskids/createagraph/default.aspx

and

“Chart Go” at:

@http://www.chartgo.com/

If you need to do a Pie Chart, there is also the “Math Warehouse Pie Chart Maker” at: @http://chartmaker.mathwarehouse.com/create-pie-chart/

First we need to go the the Kids Zone website by clicking the following link: @http://nces.ed.gov/nceskids/createagraph/default.aspx Next we click which type of graph we want to work on, such as Bar Chart:

we simply follow the instructions and make selections on graph types, style etc

and in conclusion..... media type="youtube" key="f_J8QU1m0Ng" height="315" width="560"