Julia plot function array issues

Question

Having come from Matlab I am struggling to work out why the following does not work:

plot(x=rand(10),y=rand(10))

Produces a graph correctly.

x=rand(10)
y=rand(10)
plot(x,y)

produces error:

ERROR: plot has no method matching plot(::Array(Float64,1),::Array(Float64,1))

I would be very grateful if someone coould explain to me why embeding the code within the plot line produces a result, but defining the variables beforehand results in an error. Logic says they should produce the same result.

I am using Julia v 0.3.1 and have loaded Gadfly as charting tool.

Multivalent

This gets at syntax as Toivo's answer indicates. But more generally, the plotting package you use may not have the same syntax you are familiar with. For example, Winston -- which is more MATLAB like -- uses plot(x,y) to plot the points connected by lines, as MATLAB would do and plot(x,y,"o") makes a scatter plot. Whereas Gadfly uses plot(x=x, y=y, Geom.line) to make a line graph and plot(x=x, y=y) to make a scatter plot. Alternatively, PyPlot is more similar to MATLAB than Gadfly. – Miserly

Answer 1

In the first case, you are using keyword argument syntax, not assigning to variables x and y (the meaning of = inside function calls is special). To get the same effect in the second case, you should use

x=rand(10)
y=rand(10)
plot(x=x,y=y)

which passes the value in the variable x in the keyword argument x to plot, and the value in the variable y in the keyword argument y.

Satire

Answer 2

In case you didn't. Write this before your code:

using plots
plyplot()

Retardment