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bliengme

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14 years, 18 days
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These are replies submitted by bliengme

Still 2D...

bliengme 70
February 07 2019
0 0

@Preben Alsholm 

Changing Q[inf] to Qinf (no subscript) helped but I still cannot simplify to get an exp term
 

> 

restart
> 

"P(t):=(r*Qinf)/(2+2 cosh(b-r*t))"

proc (t) options operator, arrow; r*Qinf/(2+2*cosh(b-r*t)) end proc

 (1)
> 

Q := int(P(t), t = 0 .. t)

(1/2)*Qinf*tanh((1/2)*b)-(1/2)*Qinf*tanh(-(1/2)*r*t+(1/2)*b)

 (2)
> 

simplify(Q)

-(1/2)*Qinf*(-tanh((1/2)*b)+tanh(-(1/2)*r*t+(1/2)*b))

 (3)
> 

normal(Q)

(1/2)*Qinf*tanh((1/2)*b)-(1/2)*Qinf*tanh(-(1/2)*r*t+(1/2)*b)

 (4)
> 

``


 

Download Hubbert2.mw

 

rand...

bliengme 70
January 30 2019
0 0

@acer 

Many thanks; now I have better idea of what rand does

best wishes

silly me!...

bliengme 70
January 03 2019
0 0

@Kitonum many thanks for pointing out my foolish error!

Thanks...

bliengme 70
January 03 2019
0 0

@Kitonum 

I like this but I had tried that route - see my next post


 

Thanks...

bliengme 70
January 03 2019
0 0

@acer

Got it! I* really need to be more careful 

many thanks...

bliengme 70
December 20 2018
0 0

@acer 

This is excellent

Meaning of semilog...

bliengme 70
December 19 2018
0 0

@acer 

Like you I often think semilog means log scale on one axis, linear on the other

But others use the term for a scale that has logarithmic SPACING ; as in these two diagrams



@tomleslie Thanks but I want semilog not...

bliengme 70
December 19 2018
0 0

@tomleslie Thanks but I want semilog not log. Have a look at Maple semilog to see what I mean but I wantit on the vertical xis

cheers

logplot...

bliengme 70
December 19 2018
0 0

@acer Thanks for your quick reply - again!

I rely want semilog not log. Seems to be unavailable so I will use dualaxesplot

cheers

Thnaks again...

bliengme 70
December 10 2018
0 0

@acer 

I think I should be using the Maple zoom feature to help be see silly errors like this!

Cheers

 

I upl;oaded wrong file!...

bliengme 70
December 10 2018
0 0

@Joe Riel 

Outputs 2 and 7 are the same - good

Outputs 3 and 8 differ - bad but WHYTestBoth.mw
 

> 

``
> 

restart
> 

u := -(1/2)*x^2-(1/6)*x^3+a*x+b; v := unapply(u, x)

-(1/2)*x^2-(1/6)*x^3+a*x+b

  

proc (x) options operator, arrow; -(1/2)*x^2-(1/6)*x^3+a*x+b end proc

 (1)
> 

s := solve({v(0) = 0, v(1) = 0}, {a, b})

{a = 2/3, b = 0}

 (2)
> 

assign(s)
> 

a, b

2/3, 0

 (3)
> 

v(0); v(1)

0

  

0

 (4)
> 

restart
> 

d2u := -1-x; d1u := int(d2u, x)+a; u := int(d1u, x)+b

-1-x

  

-x-(1/2)*x^2+a

  

-(1/2)*x^2-(1/6)*x^3+a*x+b

 (5)
> 

v := unapply(u, x)

proc (x) options operator, arrow; -(1/2)*x^2-(1/6)*x^3+a*x+b end proc

 (6)
> 

s = solve({v(0) = 0, v(1) = 0}, {a, b}); assign(s)

s = {a = 2/3, b = 0}

 (7)
> 

a, b

a, b

 (8)
> 

v(0); v(1)

b

  

-2/3+a+b

 (9)
> 

``


 

Download TestBoth.mwTestBoth.mw

 

But that is not automatic...

bliengme 70
December 09 2018
0 0

@Kitonum 

Your reply requires me to replace the a and b by the values from solve. But in the top part of the worksheet that happened automatically. My question is why the lower part does not behave the same as the top part

More info please...

bliengme 70
November 30 2018
0 0

@Kitonum 

I tried it and it worked

But Help does not show me the syntax for making a simplification and a change.

Can you point me to a place with info?

Thanks...

bliengme 70
November 30 2018
0 0

@Kitonum Did not know abot second paramenter in simplify - I must go back to Help

Thnak you

Perfect...

bliengme 70
November 30 2018
0 0

@acer Did not know about algsubs. Many thanks

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