This tool will generate graphs from a dataset you provide. While each type of graph has some parameters specific to it, the parameters under All Graphs apply to any type graph you choose. Note that some will be set by default, but replaced if you provide an alternative. A template file to help you generate properly formatted datasets can be dowloaded here.
Bar graphs are used to show how a continuous variable varies across groups of a categorical variable. For example, a bar graph could show how the species richness varies at three different sites.
Pie charts show the size of some value (e.g., sum or average) for each of several groups as a fraction of the total for all groups. In this way pie charts are very similar to bar graphs.
Pie charts are particularly effective when at least one "slice" is much bigger than the others. Because pie charts show relative data, they should not be used when it is necessary to compare one chart with another.
A specific type of bar graph for showing the distribution of a single variable. The x-axis has subsets of the data range (classes), and the y-axis has the frequency that data points fall into each class. See the Wikipedia article for more information (e.g., on the different formulas for determining class breaks).
If you are at the beginning stages of data analysis, plot a histogram (and/or boxplot) to assess the structure of the data (e.g., if there are outliers, if there is high/low variability, if the data fall equally on either side of the mean, etc.). Take particular note of whether or not data are "normally distributed" (i.e., follow a bell curve). Many statistical tests requires data to be normal to function properly (e.g., the t-test).
Boxplots are useful for showing the distribution of multiple datasets or groups within a datset side by side (that is, if the numbers are on the same scale). Like histograms, they are helpful for assessing variability, symmetry, and identifying outliers.
Boxplots (like histograms) help you visualize how data are distributed. The bold line in the center of the box is the median, the box itself represents the interquartile range (half of the datapoints fall within the box), and the whiskers extend to 1.5x the interqurtile range. Values outside the whiskers can be considered outliers. A boxplot is similar to a histogram, but shows the bird's eye view.
Plots a continuous variable against another continuous variable (a Y-variable vs. an X-variable). Use this when the order of values is not important (you may want to make a line graph if it is).
Each variable you list under All Graphs will be a Y-variable, and appear in a separate graph. The variables specified here are the corresponding X-variables. Please be sure the number of entries for Y and X match (e.g., 1,2,3 for Y and 4,5,5 for X; yes, a variable can be used more than once). If you have more than one factors/groups in your Y-variables, and want to plot each with a different color, designate the column containing these groups under Factor (only one column for this). Note that all groups are assumed to have the same units; it is not possible to graph multiple Y-variables against the same X-variable on different scales with this tool.
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