 ## Monday, April 1, 2013

### simple graphs with excel - things you know or might not know !

Excel is most frequently used for spread sheet application. When comes to graphics, it does great quality graphs however does not do what advanced user need to. However, many time we under estimate its ability and switch to less user-friendly and / or lower quality graphics software  In this post we will discuss on very simple graphics that excel can do (check if something is new for you):

(1) XY scatter plot
This is most common and informative graph in scientific world as it can compare two variable.

In scatter plot many times we want to add prediction lines with associate model. We can add more than one Y variable so that we can make comparison in trend.

(B) Bar (Row or Column Plots)
Bar plots are useful when categorical variable is plotted with a  numerical variable. Even if we want to plot numerical with numerical variable - one must be treated as categorical so that the bars are spaced as equal distance (not based on difference between them).

Sometime we might want to have some fancy looking 3D bar plots. They do not necessarily augment the plots, but looks nice for business charts ..

(C) Line plot
Line plot work in the same way as bar plot, however the lines are connected, useful to see a trend. In contrast XY plot where both axis are quantitative, here one variable is categorical.

We can convert any of line series to bar chart so that we can represent one variable as bar and another as line.

(D) Area plot:
Area plots are suitable in some cases where we are interested in looking area under the curve. We can overlay more than one series in the same plot.

(E) Pie chart:
Pie chart  are also popular in business charts, however their suitability in science is much argued. They are useful show composition or share of total (like percent).

### Some resources:

(1) Basic idea on how to plot graph and edit its components, see this video. Here is another video tutorial that shows how to add error bars to the plot.

(3) Video showing how we can plot multiple plot in single chart with additional axis