graphs an introduction
Download
Skip this Video
Download Presentation
Graphs An Introduction

Loading in 2 Seconds...

play fullscreen
1 / 13

Graphs An Introduction - PowerPoint PPT Presentation


  • 87 Views
  • Uploaded on

Graphs An Introduction. What is a graph?. A graph is a visual representation of a relationship between, but not restricted to, two variables.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Graphs An Introduction' - nikkos


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
what is a graph
What is a graph?

A graph is a visual representation of a relationship between, but not restricted to, two variables.

A graph generally takes the form of a one- or two-dimensional figure. Although, there are three-dimensional graphs available, they are usually considered too complex to understand easily.

A graph commonly consists of two axes called the x-axis (horizontal) and y-axis (vertical).

A graph can show Discrete or Continuous data types. Data types determines which graph to use.

discrete or continuous
Discrete or Continuous

Discrete:

Data that can be separated by some interval, for example:

Recording the shoe sizes of a class – Bar graph

Continuous:

When data collected is continuous, for example:

Recording temperature – Line graph

slide4

This is a graph

25

Y – axis

Scale or Increments

20

All graphs (except Pie Chart) have common elements:

  • Axis x and y (also z in 3D graphs)
  • Axis labels
  • A title
  • Scales or Increments
  • Can represent negative values

15

Y – axis label

10

5

Origin – does not always have to start at 0,0

X-axis

10

20

30

40

50

-20

-10

X-axis label

-5

Scale or Increments

-10

slide5

If we draw a vertical line from any point on the x-axis

Co-ordinates

25

Y – axis

and a horizontal line from the y-axis

20

A (3,15)

the point at which they meet gives us the co-ordinate

15

B (-4,10)

10

5

1

2

3

4

5

-5

-4

-3

-2

-1

-5

X-axis

-10

-15

C (-5,-15)

Back

types of graphs
Types of Graphs

Four basic types of graph or chart

Line

Pie

Bar

Scatter

line graphs

See creating a line graph presentation

Line Graphs

A good method of showing the relationship between two variables

Back

bar chart graph
Bar Chart / Graph

Used to compare values in a category or between categories.

The graph shown here makes a visual comparison of the fat content of types of cheese

bar chart graph1
Bar Chart / Graph

Can be useful to study trends over time

bar chart graph2

See creating a bar graph presentation

Bar Chart / Graph

Multiple (or group) bar graphs compare relationships of closely related sets

Back

pie charts

See creating a pie chart presentation

Pie Charts

A pie chart is used to show how a part of something relates to the whole. This kind of graph is particularly suited to showing percentages

Back

scatter graph

Weight (kg)

Height (cm)

Scatter Graph

Drawing a scatter graph is similar to drawing a line graph in that co-ordinates are used to plot the points. There are usually more points to be plotted in a scatter graph and the points can be in groups, therefore it is not possible to draw a line through all of the points.

A scatter graph shows how much correlation there is between two variables that you suspect may be linked for instance height and weight as shown here:

It is sometimes useful to draw a “line of best fit” to show the trend

Line of best fit

Back

summary
Summary

A good graph:

Accurately shows the data

Grabs the reader\'s attention

Has a title and labels

Is simple and uncluttered

Clearly shows any trends or differences in the data

Is visually accurate (i.e., if one data value is 25 and another 50, then 50 should appear to be twice the size of 25).

ad