.. py:function:: unithickness(lnsp, [levels], [lnsp_code])
.. py:function:: unithickness(lnsp, fs_levels, [lnsp_code]) :noindex: Computes the pressure thickness in Pa of a list of ECMWF model levels from ``lnsp`` (logarithm of surface pressure). :param lnsp: lnsp fieldset defined on model level 1 :type lnsp: :class:`Fieldset` :param fs_levels: fieldset defining the target model levels :type fs_levels: :class:`Fieldset` :param lnsp_code: ecCodes paramId for lnsp :type lnsp_code: number :param levels: list of target model levels whose thickness will be computed :type levels: list :rtype: :class:`Fieldset` ``lnsp`` must contain an lnsp field, which is identified by its ecCodes paramId. By default the value of 152 is used but it can be overridden by the optional ``lnsp_code``. The list of target model levels depends on the actual arguments: * if no ``fs_levels`` is specified the thickness is computed for all the model levels defined by the GRIB header in ``lnsp``. * if ``fs_levels`` is specified the thickness is computed for all the model levels in ``fs_levels``. * if ``levels`` is specified it defines the list of target model levels whose thickness will be computed. A missing value in ``lnsp`` will result in a missing value in the corresponding place in the output fieldset.
.. mv-minigallery:: unithickness