Eng. &amp; Sciences 5 (2004) 477-496.

 The letters on the different cases refer to the regions show in the
 AMPLE paper.  
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 [Svp,dSvp] = ONEDIMGIMPBASIS(xp,xv,h,lp)
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 Input(s):
 xp    - particle position
 xv    - grid node position
 h     - grid spacing 
 lp    - particle half width 
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 O