in Simulink, add line from line_node to block with command?

In Simulink, I want to add 'B4' and connect to 'A' with command, I want it to look like bellow:

I tried the code of add_line(gcs, 'A/1', 'B4/1', 'autorouting', 'on'). but it looks like bellow:

Then my new idea is add_line from 'P1_position' to 'B4'. while I do not know how to get the 'P1_position' or 'Line3_length'(to calcute P1_position).

Thanks to all viewing/answering my question!

Answer 1

[Fangjun Jiang]

If you know that the connection can be started from block B3, then you can get the line handles of B3, then get the line handle of Line 3, then get the 'Points' of Line 3.

I've been able to add the line directly from P1 to block B4 inport (get its position first), but 'autorouting' is not available when using add_line with points. You need to generate the way point based on the coordinates of point P1 and B4 inport point. I think it can be done.

[Leo Zhai]

Thanks for your answer:

while, I did not understand

"If you know that the connection can be started from block B3, then you can get the line handles of B3, then get the line handle of Line 3, then get the 'Points' of Line 3."

(1) "connection can be started from block B3" - which connection?

(2) "get the line handles of B3, then get the line handle of Line 3" - I used the bellow command of

get_param([gcs, '/B3'], 'LineHandles'); but I do not know conitnue to "get the line handle of Line 3, then get the 'Points' of Line 3"

Then, If I know the P1_position is e.g. [365 330], then I will use

get_param([gcs, '/B4'], 'PortConnectivity'); to get B4_inport position,

then add_line(gcs, [365 330; 365 370; 390 370]); to finish the line.

[Fangjun Jiang]

1. Your task is to connect from A to B4 and make the line pretty. In program, you have to decide where to start this new line. From P1 or the junction points above it (the intersection point of the vertical line with horizontal input line of B2 or B1). If you know it is P1 which actually means the block B3 is known, then it makes this task a little easier.
2. Use this code. You will get the position of P1 from the points of B3 input line

lh=get_param([gcs,'/B3'],'LineHandles');
lh_inport=lh.Inport;
get_param(lh_inport,'Points')

[Leo Zhai]

Thank you very much, the bellow is exactly what I wanted.

get_param(lh_inport,'Points')

(I had tried get_param(lh_inport, 'ObjectParameters') to search 'line_length' parameters but got none...)