Override branch angles

[dan-knight]

Description

Closes #93: These changes allow optional angle overrides in tree input. These overrides do not affect the angle calculations (or, in other words, other angles are not calculated in relation to overridden angles). A new angle.unit parameter was added to the top-level SRCGrob function to allow angles to be specified in either radians or degrees.

Default Angles

tree.df <- data.frame(
    parent = c(NA, 1, 2, 2)
    );

tree.plot <- SRCGrob(tree.df);
grid.draw(tree.plot);

With Angle Override

tree.df <- data.frame(
    parent = c(NA, 1, 2, 2),
    angle = c(NA, NA, 90, NA)
    );

tree.plot <- SRCGrob(tree.df);
grid.draw(tree.plot);

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[whelena]

Why did the R-CMD-check failed? It seems there's a mismatch in the documentation?

[dan-knight]

It seems there's a mismatch in the documentation?

Ah, yep. I added a parameter to SRCGrob. Easy fix - on it.