A heat graph is frequently used come display change over time together a series of data points connected by straight line segment on 2 axes. The heat graph therefore helps to determine the relationship in between two set of values, through one data collection always gift dependent top top the various other set.

You are watching: Describe the graph of y > mx, where m > 0.

Line graphs are drawn so that the independent data room on the horizontal a-axis (e.g. Time) and the dependency data room on the vertical y-axis.Line graphs are used to track transforms over short and long periods of time.There is part debate around the level of measurement in between time points. Some say the data must be measured almost continually in order because that the lines come be precise representations. Others feel a monthly measurement is sufficient, even though the line indicates data in ~ points wherein no measurement was taken.

Line graphs are beneficial in that they display data variables and also trends very clearly and can assist to do predictions about the results of data not yet recorded. Lock can additionally be provided to display several dependence variables against one elevation variable. As soon as comparing data sets, line graphs space only beneficial if the axes follow the very same scales. Some professionals recommend no an ext than 4 present on a solitary graph; any an ext than that and also it becomes daunting to interpret.

"Line graphs and also scatterplotsare similar in the they record individual data worths as marks on a graph. The difference in between these two styles is exactly how the line is created. In line graphs, the line is created by connecting every individual data point to present local changes, in this way, the local change from suggest to point can it is in seen. This is done when it is important to have the ability to see the local change between pair that points. An in its entirety trend can still be seen, yet this trend is joined by the local trend in between individual or tiny groups that points, vice versa, the heat of the scatterplot go not attach individual points yet instead reflects the trend complied with by the data."

Line graphs that connect only two points in time are referred to as slope graphs. These deserve to be handy once you don’t have actually data for each time period, however want to compare, because that example, the start of the program in 1986 to the current state the the routine in 2014. Use these if friend don’t have other data to show program outcomes.

### Example

The differencein median household income between California and also the rest of the unified States

This example from the California budget plan Project is anexample of a heat chart showing readjust in median family members income in California between 1989 and also 2010. The colour distinction outlines the difference in between California and the unified States

Source: www.cbp.org/pdfs/2012/TestImages/Second%20Test/line-chart-template.png

Red river discharge rate per month in 1993

"This example might have additionally been created as a bar graph. Friend would use a line graph once you want to be able to more plainly see the rate of adjust (slope) between individual data points. If the independent variable to be nominal, friend would almost certainly use a bar graph rather of a line graph."

"Here, we have actually taken the very same graph seen over and added a second independent variable, year. Both the elevation variables, month and year, deserve to be treated as being either as ordinal or scalar. This is regularly the case with bigger units the time, such as weeks, months, and also years. Because we have actually a second independent variable, some type of coding is necessary to indicate which level (year) every line is. Though we could label each bar with message indicating the year, that is an ext efficient to usecolorand/or a various symbol on the data points. We will need a legend to explain the coding scheme.

Multiple heat graphs have space-saving features over a similar grouped bar graph. Due to the fact that the data values are significant by small marks (points) and also not bars, they perform not need to be counter from each other (only as soon as data values are an extremely dense go this become a problem). Another benefit is that the lines deserve to easily dual coded. Through the lines, they deserve to both becolorcoded (for computer andcolorprint display) or form coded with icons (for black color & white reproduction). V bars, form coding cannot be used, and also pattern coding has to be substituted. Sample coding tends to it is in much an ext limiting.

Notice the there is a rest in the 1996 data heat (green/triangle) in between August and also October. Due to the fact that the data allude for September is missing, the line have to not be linked between August and also October because this would offer an erroneous regional slope. This is specifically important if you screen the line without icons at separation, personal, instance data points."

Source: Wallace, (2005)www.ncsu.edu/labwrite/res/gh/gh-linegraph.html#multipleline

Advice for choosing this choice (tips and traps)

Line graphs are usually provided to represent transforms over time.

Advice for using this choice (tips and also traps)

As finest as possible, label the line through its name rather than utilizing a legend.

Highlight crucial points in the line through the exact value, such as the highest and also lowest point out or those points where actual data collection occured.

### Resource

Example

Line Graphs and Scatter Plots: This website from north Carolina State University has actually guided instances forusing heat graphs.