Draw symmetric shape (normal distribution) with pen tool

[jake19]

Hi,

I am new to affinity designer and hoping to draw some schematics of normal distributions under different situations (see attached image for what I am trying to draw). I am using the pen tool, but having trouble getting the left and right side to be symmetric. I am trying to essentially create a schematic that looks like the attached image and be able to adjust the height and width of the distributions. I think this should be straightforward, but not sure what options to use with the pen tool to easily do this and would appreciate some help.

 

Thank you

generating-normal-random-variables-part-1_4_0.svg

Edited May 22, 2021 by jake19

[firstdefence]

This is the graphic turned into a png for better visuals.

[G13RL]

Hi @jake19,

You can simply place the various points of the curve at the desired locations using a reference grid.
Select nodes 2 and 3, round them with the Corner Tool. Then do the same for node 4 (with a different value).
Select all three nodes (2, 3, 4), "Convert to Smooth" (in the context bar).
Align horizontally and equalize the length of the handles on node 4.
Align horizontally and equalize the length of the handles of nodes 2 and 3 to achieve bottom symmetry.
Repeat for each curve, placing Nodes 1 and 5 in the same location as the first curve.

[loukash]

8 hours ago, jake19 said:

I think this should be straightforward, but not sure what options to use with the pen tool to easily do this and would appreciate some help.

Read the whole "Drawing curves and shapes" section in affinity.help/designer (online, also available offline in your app). Also always watch the contextual info bar at the bottom of the window for modifier options. Check out the snapping options in Snapping manager as well as the extra snapping options in the context toolbar for the Pen and Node tools.

In general, I'd begin with a straight line with three "smooth" nodes, then I'd simply raise the middle one on the y axis. Adjust handles as you see fit by using the various align and snapping helpers.

[loukash]

You may also want to create a custom grid in the Grid Manager to match your graph, then turn on snapping to grid.

[firstdefence]

1 hour ago, G13RL said:

Hi @jake19,

You can simply place the various points of the curve at the desired locations using a reference grid.
Select nodes 2 and 3, round them with the Corner Tool. Then do the same for node 4 (with a different value).
Select all three nodes (2, 3, 4), "Convert to Smooth" (in the context bar).
Align horizontally and equalize the length of the handles on node 4.
Align horizontally and equalize the length of the handles of nodes 2 and 3 to achieve bottom symmetry.
Repeat for each curve, placing Nodes 1 and 5 in the same location as the first curve.

First step: 1,2,3,4,5 once I caught a fish alive... 😆 

[G13RL]

@firstdefence, being french speaking, I had to do some research to discover this nursery rhyme! 😊

[firstdefence]

25 minutes ago, G13RL said:

@firstdefence, being french speaking, I had to do some research to discover this nursery rhyme! 😊

lol!