Negative value for Graph

Thanks Pier

I can't visualize what could, even theoretically, be graphed to a negative value. Could you give an example?

David Janes

Janes ha scritto:

value. Could you give an example?

If you draw a graph, you have a 2d-coordinate-system with X axs and Y axs which, for instance drives the angle of a sketch . The Y values could be negative ?

I hope to have been clear. Bye

If you draw a graph, you have a 2d-coordinate-system with X axs and Y axs which, for instance drives the angle of a sketch . The Y values could be negative ?

I hope to have been clear. Bye I see how the values could be negative, at least for the graph. But why not just move all of it above the zero line? The problem you're running into is the dual use of the negative sign as an operator (directional) and as an absolute value. Your graph no doubt has the negatives as absolute values while the operation of moving the angle can't deal with the absolute negative values since you couldn't manaully put them in a sketch. So, for example, if you dragged your line segment with the five degree angle to the other side of the dimensioning reference, it still wouldn't be~would NEVER be~a minus 5 degree angle. If you can't do it manually in a sketch, you can't make a graph do it either.

David Janes

value. Could you give an example?

just move all of it above the zero line? The problem you're running into is the dual use of the negative sign as an operator (directional) and as an absolute value. Your graph no doubt has the negatives as absolute values while the operation of moving the angle can't deal with the absolute negative values since you couldn't manaully put them in a sketch. So, for example, if you dragged your line segment with the five degree angle to the other side of the dimensioning reference, it still wouldn't be~would NEVER be~a minus 5 degree angle. If you can't do it manually in a sketch, you can't make a graph do it either.

I've just done a quick check with a graph crossing into the second quadrant (-y) and used to made a variable sweep behaving as I'd expect except that saying something is negative only means that it appears in a certain quadrant, it cannot have a real negative value. BTW, an actual negative value in the second quadrant of the graph also gives a meaningful result in the sweep.