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Hi,</div>
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<div>I am a Ph.D. student at the Indian Institute of Science, Bangalore, India.</div>
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I have been working on a project that requires a polyhedron. <br>
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The polyhedron has constraints with floating-point variables, as shown below in the following code snippet.</div>
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Wher <i><b>p,u,v </b></i>and w are f<b>loating-poin</b>t values <b>between 0 and 1, u+v+w =1.</b></div>
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<span><span style="color:#569cd6">
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<span><span style="color:#4ec9b0">Variable</span><span> </span><span style="color:#9cdcfe">xp0</span><span>(</span><span style="color:#b5cea8">0</span><span>);</span></span>
<div><span style="color:#4ec9b0">Variable</span><span> </span><span style="color:#9cdcfe">yp0</span><span>(</span><span style="color:#b5cea8">1</span><span>);</span></div>
<div><span style="color:#4ec9b0">Variable</span><span> </span><span style="color:#9cdcfe">zp0</span><span>(</span><span style="color:#b5cea8">2</span><span>);</span></div>
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<div><span style="color:#4ec9b0">Variable</span><span> </span><span style="color:#9cdcfe">u</span><span>(</span><span style="color:#b5cea8">0</span><span>);</span></div>
<div><span style="color:#4ec9b0">Variable</span><span> </span><span style="color:#9cdcfe">v</span><span>(</span><span style="color:#b5cea8">1</span><span>);</span></div>
<div><span style="color:#4ec9b0">Variable</span><span> </span><span style="color:#9cdcfe">w</span><span>(</span><span style="color:#b5cea8">2</span><span>);</span></div>
<div><span style="color:#4ec9b0">Variable</span><span> </span><span style="color:#9cdcfe">p</span><span>(</span><span style="color:#b5cea8">0</span><span>);</span></div>
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<span><span style="color:#569cd6"><br>
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<span><span style="color:#569cd6">int</span><span> x0 = </span><span style="color:#9cdcfe">vertices</span><span>[insideVertex*</span><span style="color:#b5cea8">3</span><span>+</span><span style="color:#b5cea8">0</span><span>];</span></span>
<div><span style="color:#569cd6">int</span><span> y0 = </span><span style="color:#9cdcfe">vertices</span><span>[insideVertex*</span><span style="color:#b5cea8">3</span><span>+</span><span style="color:#b5cea8">1</span><span>];</span></div>
<div><span style="color:#569cd6">int</span><span> z0 = </span><span style="color:#9cdcfe">vertices</span><span>[insideVertex*</span><span style="color:#b5cea8">3</span><span>+</span><span style="color:#b5cea8">2</span><span>];</span></div>
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<div><span style="color:#569cd6">int</span><span> x1 = </span><span style="color:#9cdcfe">vertices</span><span>[outsideVertex*</span><span style="color:#b5cea8">3</span><span>+</span><span style="color:#b5cea8">0</span><span>];</span></div>
<div><span style="color:#569cd6">int</span><span> y1 = </span><span style="color:#9cdcfe">vertices</span><span>[outsideVertex*</span><span style="color:#b5cea8">3</span><span>+</span><span style="color:#b5cea8">1</span><span>];</span></div>
<div><span style="color:#569cd6">int</span><span> z1 = </span><span style="color:#9cdcfe">vertices</span><span>[outsideVertex*</span><span style="color:#b5cea8">3</span><span>+</span><span style="color:#b5cea8">2</span><span>];</span></div>
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<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( u+v+w ==
</span><span style="color:#b5cea8">1</span><span>);</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( u>=</span><span style="color:#b5cea8">0</span><span>) ;</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( v>=</span><span style="color:#b5cea8">0</span><span>);</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( w>=</span><span style="color:#b5cea8">0</span><span>);</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( p>=</span><span style="color:#b5cea8">0</span><span>);</span></div>
<div><span style="color:#6a9955">// pd->add_constraint( q>=0);</span></div>
<div><span style="color:#6a9955">// pd->add_constraint( p+q ==1);</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( ( (( p*(x0 - xp0)+ (</span><span style="color:#b5cea8">1</span><span>-p)*(x1 - xp0)) == (u*-</span><span style="color:#b5cea8">35821</span><span>+v*</span><span style="color:#b5cea8">0</span><span>+(w)*</span><span style="color:#b5cea8">35821</span><span>))
);</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( ((p*(y0 - yp0)+ (</span><span style="color:#b5cea8">1</span><span>-p)*(y1 - yp0)) == (u*</span><span style="color:#b5cea8">35821</span><span>+v*</span><span style="color:#b5cea8">0</span><span>+(w)*</span><span style="color:#b5cea8">35821</span><span>))
);</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( ((p*(z0 - zp0)+ (</span><span style="color:#b5cea8">1</span><span>-p)*(z1 - zp0)) == (u*-</span><span style="color:#b5cea8">100000</span><span>+v*</span><span style="color:#b5cea8">0</span><span>+(w)*-</span><span style="color:#b5cea8">100000</span><span>)));</span></div>
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<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( -( (</span><span style="color:#b5cea8">24</span><span>*p*(x0-xp0))+(</span><span style="color:#b5cea8">24</span><span>*(</span><span style="color:#b5cea8">1</span><span>-p)*(x1-xp0)))
>= ((PixelX - </span><span style="color:#b5cea8">24</span><span>)*(p*(z0-zp0)+ (</span><span style="color:#b5cea8">1</span><span>-p)*(z1-zp0)) ) );</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( -( (</span><span style="color:#b5cea8">24</span><span>*p*(x0-xp0))+(</span><span style="color:#b5cea8">24</span><span>*(</span><span style="color:#b5cea8">1</span><span>-p)*(x1-xp0)))
< ((PixelX+</span><span style="color:#b5cea8">1</span><span> - </span><span style="color:#b5cea8">24</span><span>)*(p*(z0-zp0)+ (</span><span style="color:#b5cea8">1</span><span>-p)*(z1-zp0)) ) );</span></div>
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<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( (
</span><span style="color:#b5cea8">24</span><span>*p*(y0-yp0) + </span><span style="color:#b5cea8">24</span><span>* (</span><span style="color:#b5cea8">1</span><span>-p)*(y1-yp0) ) >= ( (PixelY-</span><span style="color:#b5cea8">24</span><span>) * (p*(z0-zp0)+
(</span><span style="color:#b5cea8">1</span><span>-p)*(z1-zp0)) ) );</span></div>
<div><span style="color:#9cdcfe">pd</span><span>-></span><span style="color:#dcdcaa">add_constraint</span><span>( (
</span><span style="color:#b5cea8">24</span><span>*p*(y0-yp0) + </span><span style="color:#b5cea8">24</span><span>* (</span><span style="color:#b5cea8">1</span><span>-p)*(y1-yp0) ) < ( (PixelY-</span><span style="color:#b5cea8">24</span><span>+</span><span style="color:#b5cea8">1</span><span>)
* (p*(z0-zp0)+ (</span><span style="color:#b5cea8">1</span><span>-p)*(z1-zp0)) ) );</span></div>
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<span style="font-size:12pt">While compiling the program, I am getting the following error;</span><br>
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error: no match for ‘operator*’ (operand types are ‘Parma_Polyhedra_Library::Variable’ and ‘Parma_Polyhedra_Library::Linear_Expression’)
<div> 116 | pd->add_constraint( ( (( p*(x0 - xp0)+ (1-p)*(x1 - xp0)) == (u*-35821+v*0+(w)*35821)) );</div>
<div> | ~^~~~~~~~~~~</div>
<div> | | |</div>
<div> | | Parma_Polyhedra_Library::Linear_Expression</div>
<span> | Parma_Polyhedra_Library::Variable</span><br>
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Is there any way to get rid of this error?</div>
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Is it possible to write my constraints using PPL (using either floating-point expression or intervals)?<br>
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Thanks</div>
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HABEEB<br>
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