Thank you!

Hello,

I am trying to keep tab of the number of times that a curve passes a certain line but I can't get the counter to work (i++ style).

e.g.:
algorithm
  if  y==constant  then
        i:=i+1
  end if;

This only makes i:=i+1 at the moment when condition is true.. afterwards it reverts to its old value.  How do I change it for good?

Help is much appreciated.

Hi,

I have been repeatedly having this error when adjusting certain parameters for my simulation (using Dymola 7.1).  At this point I cannot avoid it anymore and need to solve it to continue my work.

Does anyone have a clue as to how to approach this?

The following error was detected at time: 0.08644948974278317
The arguments x_min and x_max to OneNonLinearEquation.solve(..)
do not bracket the root of the single non-linear equation:
  x_min  = 200
  x_max  = 6000
  y_zero = 133830
  fa = f(x_min) - y_zero = 66313.2
  fb = f(x_max) - y_zero = 7.38427e+006
fa and fb must have opposite sign which is not the case
The stack of functions is:
Internal.solve_Unique'"16EACA28"'
Modelica.Media.Air.DryAirNasa.T_h_Unique'"13825900"'
Modelica.Media.Air.DryAirNasa.setState_phX_Unique'"15F37938"'
Modelica.Media.Air.DryAirNasa.setState_phX_Unique'"15F37938"'(volume1.medium.p, volume1.ports[1].h_outflow, volume1.ports[1].Xi_outflow)

Thank you,

Christian

Hmm I'm still having trouble. I will stick to using Dymola for Fluids for now.
Thank you very much for your help!

Christian

Thank you, but unfortunately I'm still confused about it:

I have the exact copy of the Fluid folder from Modelica 3.2 and it contains the file "package.mo" in it.  Am I using the right name and value? or is it in the right directory?

Cheers
Christian

Hi,

so I am still having problems importing.

I moved my "Fluid" folder into C:\OpenModelica1.8.0\lib\omlibrary.

Then when adding a new library in the options, I typed in:
"Fluid" as name and "default" as value.

I try resetting the programming and nothing changes. What am I doing wrong?

(I am using the OpenModelica revision 10304)

Thanks!

Christian

Oh yea.. Im using a beta of 1.8 which doesn't have that option

Thanks a lot!

Hi,

This sounds very simple but I can't seem to figure out how to open in OMEdit say the library Modelica_Fluid 1.0. I can't find an option for importing a library and inserting the files into the modelica library folders doesn't do anything.  I also tried to open .mo files in the Fluid library but the software just freezes.

Please, if anyone has a clue, could you help me with this?

Thanks in advance,

Christian

Hi

I am using OM 1.8.0 and trying the pendulum example.  It fails at about 0.2 sec because it is not converging. Is this a bug?

Here is my input and the message I get:

class Pendulum "Planar Pendulum"
  constant Real PI = 3.14159265358979;
  parameter Real m = 1,g = 9.81,L = 0.5;
  Real F;
  output Real x(start = 0.5),y(start = 0);
  output Real vx,vy;
equation
  m * der(vx) = -(x / L) * F;
  m * der(vy) = -(x / L) * F - m * g;
  der(x) = vx;
  der(y) = vy;
  x ^ 2 + y ^ 2 = L ^ 2;
end Pendulum;




Simulated 'Pendulum' successfully! with message:
DASSL--  AT CURRENT T (=R1)  500 STEPS
      In above message,  R1 =   .2054502887339E+00
DASSL--  TAKEN ON THIS CALL BEFORE REACHING TOUT
| warning | DDASRT: A large amount of work has been expended.(About 500 steps). Trying to continue ...
DASSL--  AT CURRENT T (=R1)  500 STEPS
      In above message,  R1 =   .2054502887357E+00
DASSL--  TAKEN ON THIS CALL BEFORE REACHING TOUT
| warning | DDASRT: A large amount of work has been expended.(About 500 steps). Trying to continue ...
DASSL--  AT CURRENT T (=R1)  500 STEPS
      In above message,  R1 =   .2054502887362E+00
DASSL--  TAKEN ON THIS CALL BEFORE REACHING TOUT
| warning | DDASRT: A large amount of work has been expended.(About 500 steps). Trying to continue ...
DASSL--  AT CURRENT T (=R1)  500 STEPS
      In above message,  R1 =   .2054502887364E+00
DASSL--  TAKEN ON THIS CALL BEFORE REACHING TOUT
| warning | DDASRT: A large amount of work has been expended.(About 500 steps). Trying to continue ...
DASSL--  AT T (=R1) AND STEPSIZE H (=R2) THE
      In above,  R1 =   .2054502887365E+00   R2 =   .1164869998510E-15
DASSL--  CORRECTOR FAILED TO CONVERGE REPEATEDLY
DASSL--  OR WITH ABS(H)=HMIN

Error in Simulation. Solver exit with error.

| error | DDASRT: The corrector could not converge.