huyanzhuo, We compute and then output data inside DataOut<dim> as float (32 bit floating point) and not as double (64bit). Float has an accuracy of approximately 7 decimal digits, so your number would be roughly 1647.999 but it happens to be rounded up to 1648.000. I am afraid there is no easy way to change this because this is hard-coded inside DataOut<dim>. It is in the Patch class if you are curious: https://www.dealii.org/developer/doxygen/deal.II/structDataOutBase_1_1Patch.html#a366bf92bcc2b667586d630455953d911
Normally, this should be enough for visualization. On Tue, Feb 8, 2022 at 4:58 PM huyanzhuo <[email protected]> wrote: > > I'm using the 8.5.1 version. > As the theme side, i gives a vector to a DataOut<dim> object, the type of > the vector entry is double, with 15 effective digit. But there is only 6 > digit when write to a file (vtk or gpl). My vector is around 1647.99932xxxx, > the result write into the file is 1648. How can i improve the presion of the > result in file? > > -- > The deal.II project is located at http://www.dealii.org/ > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > --- > You received this message because you are subscribed to the Google Groups > "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/dealii/db91c18b-7e9b-4aa0-9a81-3e93e1f3df2an%40googlegroups.com. -- Timo Heister http://www.math.clemson.edu/~heister/ -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/CAMRj59GUHB9ZqmwjuScjrfuyb8XSuz%2BCg-ZbX24i22cGUdLURA%40mail.gmail.com.
