Subtracting list from a variable

[borderliner]

Hi, I've created a list and want to subtract all the values within it from another variable, and assign it to a new variable.

How do I do it?

Basically, I ask for ground level (assigned to variable G1), and then any number of depths beneath that (assign to list LVLLIST), and I want to return the value of the bottom point. So it's all the values in LVLLIST added together and subtracted from G1. And assign it to a new variable BASE.

Me thinks anyway.

For example,

G1 = 650.00

LVLLIST = (1.23 23.26 0.13 50.23)

(setq BASE (- G1 LVLLLIST))

Thanks

[Kent1Cooper · Accepted solution]

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@borderliner wrote:

.... I ask for ground level (assigned to variable G1), and then any number of depths beneath that (assign to list LVLLIST), and I want to return the value of the bottom point. So it's all the values in LVLLIST added together and subtracted from G1. And assign it to a new variable BASE.

....

G1 = 650.00

LVLLIST = (1.23 23.26 0.13 50.23)

(setq BASE (- G1 LVLLLIST))

....

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This is an application for the (apply) function:

(setq BASE (- G1 (apply '+ LVLLLIST)))

[borderliner]

Spot on.

Thanks.

First ever LISP routine - and feelin' quite good about it...