The insert circle plugin that comes with Graph isn't working either. Is there something that is preventing dialog boxes from opening up?]]>

Yet again you've rescued me!

I'll try it - glad it gave you something new!

Pete]]>

Graph calculates a lot of points. When *Lines* is chosen, Graph will simply connect all the points with lines. When *Automatic* is chosen, Graph tries to be smart and only connect the points it thinks should be connected. For example it will not show a vertical line at x=0 for f(x)=1/x.

In this case *Automatic* fails. Apparent the slope is so steep that Graph thinks it is jumping like f(x)=1/x does. I think it is the first time I have seen it failing.

Example : x^2 + 5x + 6

To clarify : I determine a range of values of 'x' to be substituted in the equation, in this case -6 to +6

There are 2 functions FX1 & FX2. and 2 independent values X1 & X2

X2 is 0.0000001 greater than X1, these are substituted into FX1 & Fx2 and the results are checked for difference in signs.

Any 'crossover' is stored.

X1 is stepped to the X2 value and X2 is stepped by Delta (0.0000001)

Hope that makes sense!

I tried a rather 'difficult' equation :

28x13 + 125.76x12 - 99.4285x11 - 56.6228x9 + 442.12x5 + 114x4 - 220.08x3 + 76x2 - 149.34

and got these results :

* No Rational roots found *

3 irrational root(s)

between

-5.1899587195 and -5.1899587194 y

-0.9452824780 and -0.9452824779

0.8321704412 and 0.8321704413

but using Graph only displayed the last 2 - any ideas?

Regards

Pete

Typically the X axis is from small to large numbers.

What should I do to reverse it. For example to draw a function starting with the value of 10 at the origin and ending at the value of zero.

Thanks]]>

Did you get the same/similar results ?

Graph gives the following roots for the function, which are the same you have found:

-0.92669868427

0.92669783476

0.95911999503

1.06415303253

currently multiplying the 1st coefficient by the constant, which I try in the equation in steps of 1 / 1000000000!

This can lead to (say) 10 minutes calculation - can you give me any idea how to narrow this down ?

I am not sure what exactly it is you are trying to do, which makes it a little difficult to give suggestions.

I gather you are either a mathematician or a programmer - or both - yes?

Well, I have an education as electrical engineer, but I have only been working with software development.

]]>I think before the week is over you'll be fed up with my questions!

If so, just say - I'll leave off!

In my program I have to determine a range of 'x' values to check - I'm

currently multiplying the 1st coefficient by the constant, which I try in the equation in steps of 1 / 1000000000!

This can lead to (say) 10 minutes calculation - can you give me any idea how to narrow this down ?

I gather you are either a mathematician or a programmer - or both - yes?

Excellent program (Graph).

Pete]]>

Will save me 'hunting' around!

Did you get the same/similar results ?

I must get down to reading the manual!

Pete]]>

It does it's job and I use "Graph" to confirm my results.

But I have a 'large' equation that my program don't agree!

The equation is :

48x^22 + 32x^20 + 81.12x^18 - 252.64x^14 - 149.1428x^13 + 125.76x^12 - 99.4285x^11 - 56.6228x^9 + 442.12x^5 + 114x^4 - 220.08x^3 + 76x^2 - 149.34

I get :

* No Rational roots found *

4 irrational root(s)

between

-0.9266986843 and -0.9266986842 y

0.9266978347 and 0.9266978348

0.9591199950 and 0.9591199951

1.0641530325 and 1.0641530326

Sorry, but I'm partially blind and am having difficulty reading the graph.

Do you agree with my results ?

Can you help please ?

Pete