# Board index » delphi » Plotting a Sin graph

## Plotting a Sin graph

Hi there,
Thanks once again to everyone for their help.

We started doing Sin graphs this year, but I can't plot one using
Pascal.  I only tried plotting points untill I can figure out a way to
connect them.  But I have a problem.  Sin(45) equals 0.??? .  How does
one plot that?  I tried multyplying it by 100, but then the points do
not make the normal pattern.  Is there a way to do this?  I know one can
work out the coordinates for all the x values from 1 to 360 by hand and
then store it in an Array, but there has to be an easier way.  Any help
will be appreciated.

Johan Kohler
johan.koh...@als.co.za

## Re:Plotting a Sin graph

##### Quote
JOHAN KOHLER wrote:
> We started doing Sin graphs this year, but I can't plot one using
> Pascal.  I only tried plotting points untill I can figure out a way to
> connect them.  But I have a problem.  Sin(45) equals 0.??? .  How does
> one plot that?  I tried multyplying it by 100, but then the points do
> not make the normal pattern.  Is there a way to do this?  I know one
> can work out the coordinates for all the x values from 1 to 360 by
> hand and then store it in an Array, but there has to be an easier way.

Function Sin(<angle in RADIANS>: Real): Real;

AME

## Re:Plotting a Sin graph

-=> Quoting Alan M  Evans to All <=-

AME> JOHAN KOHLER wrote:

> We started doing Sin graphs this year, but I can't plot one using
> Pascal.  I only tried plotting points untill I can figure out a way to
> connect them.  But I have a problem.  Sin(45) equals 0.??? .  How does
> one plot that?  I tried multyplying it by 100, but then the points do
> not make the normal pattern.  Is there a way to do this?  I know one
> can work out the coordinates for all the x values from 1 to 360 by
> hand and then store it in an Array, but there has to be an easier way.

AME> Function Sin(<angle in RADIANS>: Real): Real;

AME> Pi radians := 180 degrees

Line 1 I understand - it is the Sin function in TP.  But how do radians work?
Normal degrees go (from top clockwise) 0, 90, 180, 270.  What is the order

Groete uit Suid-Afrika        -
Greetings from South Africa   -          Johan Khler
Salutojn de Sud-Afriko        -          johan.koh...@als.co.za
___ Blue Wave/DOS v2.30 [NR]

## Re:Plotting a Sin graph

In article <8D8840D.05F1001B04.uu...@als.co.za>, JOHAN KOHLER
<johan.koh...@als.co.za> writes

##### Quote
> AME> Function Sin(<angle in RADIANS>: Real): Real;

> AME> Pi radians := 180 degrees

>Line 1 I understand - it is the Sin function in TP.  But how do radians work?
>Normal degrees go (from top clockwise) 0, 90, 180, 270.  What is the order

etc.

The reason radians are used, is because, well you know the circumference
of an arc with degrees is (angle/180)*Pi*r

Using radians it's just the angle*radius, which is a hell of a lot
simpler..

Anyway, I don't think this is really relevant right now..

Lots of love
--
,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.
Michael Stephenson      @(^_^)(^_^)@    mich...@jlmaa.demon.co.uk
-+-+*+-+**+-+*+-+-                      http:\\www.jlmaa.demon.co.uk
Proleteri svih zemalja ujedinite se !   PinkFrog on IRC-Net
+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.+'`'+.,.

## Re:Plotting a Sin graph

Hi there,

-=> Quoting Michael Stephenson to All <=-

MS> 0   degrees = 0     radians
MS> 90  degrees = Pi/2  radians
MS> 180 degrees = Pi    radians
MS> 270 degrees = 3Pi/2 radians

Thanks a lot for your help.  I have just asked my Computer Studies teacher
today and that's basically what she came up with.  I will try it and yell
if I have any more problems :)

Thanks again.

Groete uit Suid-Afrika        -
Greetings from South Africa   -          Johan Khler
Salutojn de Sud-Afriko        -          johan.koh...@als.co.za
___ Blue Wave/DOS v2.30 [NR]