Probably one of the most important aspects of data science is in visualizing data. This means: to make a plot (or graph) out of it.

Since charts are made of rows of data, arrays will be a natural way of holding and presenting your data to the chart drawing function. In the simplest case, a chart has two rows, one for the $x$, or horizontal axis, and one for $y$, or the vertical axis.

There is one little issue here: the sample.dat file only contains one column of numbers. What do we do about the other column? Make it up! We'll put the actual data on the y-axis, and make up the x-axis to just be the data point's position in the file (1,2,3,...)

To make the plot, we'll use drawchart which works like this:

Move the mouse over a dotted box for more information.

A chart will always appear at the very bottom of the browser window. You might have to scroll down to see it.

x = {}

y = {}

​

h = file_open("sample.dat")

if h == false then 

 print("File can't be used.")

 return 

end

​

i = 1

repeat

 data = ??

 if data ~= false then

  x[i] = i

  y[i] = ??

  i = i + 1

 end

until data == false

drawchart(x,y,"line")