| | |
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| | | return TS_SUCCESS; |
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| | | }; |
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| | | |
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| | | /** @brief Calculation of energy of the vertex |
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| | | /** @brief Calculation of the bending energy of the vertex. |
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| | | * |
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| | | * Main function that calculates energy of the vertex \f$i\f$. Nearest neighbors (NN) must be ordered in counterclockwise direction for this function to work. |
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| | | * Main function that calculates energy of the vertex \f$i\f$. Function returns \f$\frac{1}{2}(c_1+c_2-c)^2 s\f$, where \f$(c_1+c_2)/2\f$ is mean curvature, |
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| | | * \f$c/2\f$ is spontaneous curvature and \f$s\f$ is area per vertex \f$i\f$. |
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| | | * |
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| | | * Nearest neighbors (NN) must be ordered in counterclockwise direction for this function to work. |
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| | | * Firstly NNs that form two neighboring triangles are found (\f$j_m\f$, \f$j_p\f$ and common \f$j\f$). Later, the scalar product of vectors \f$x_1=(\mathbf{i}-\mathbf{j_p})\cdot (\mathbf{i}-\mathbf{j_p})(\mathbf{i}-\mathbf{j_p})\f$, \f$x_2=(\mathbf{j}-\mathbf{j_p})\cdot (\mathbf{j}-\mathbf{j_p})\f$ and \f$x_3=(\mathbf{j}-\mathbf{j_p})\cdot (\mathbf{i}-\mathbf{j_p})\f$ are calculated. From these three vectors the \f$c_{tp}=\frac{1}{\tan(\varphi_p)}\f$ is calculated, where \f$\varphi_p\f$ is the inner angle at vertex \f$j_p\f$. The procedure is repeated for \f$j_m\f$ instead of \f$j_p\f$ resulting in \f$c_{tn}\f$. |
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| | | * |
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| | | \begin{tikzpicture}{ |
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| | |
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| | | #endif |
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| | | // c is forced curvature energy for each vertex. Should be set to zero for |
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| | | // normal circumstances. |
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| | | /* the following statement is an expression for $\frac{1}{2}\int(c_1+c_2-c_0^\prime)^2\mathrm{d}A$, where $c_0^\prime=2c_0$ (twice the spontaneous curvature) */ |
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| | | vtx->energy=0.5*s*(vtx->curvature/s-vtx->c)*(vtx->curvature/s-vtx->c); |
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| | | |
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| | | return TS_SUCCESS; |
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| | |
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| | | } |
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| | | return TS_SUCCESS; |
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| | | } |
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| | | |
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| | | ts_double direct_force_energy(ts_vesicle *vesicle, ts_vertex *vtx, ts_vertex *vtx_old){ |
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| | | if(fabs(vtx->c)<1e-15) return 0.0; |
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| | | // printf("was here"); |
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| | | if(fabs(vesicle->tape->F)<1e-15) return 0.0; |
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| | | |
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| | | ts_double norml,ddp=0.0; |
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| | | ts_uint i; |
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| | | ts_double xnorm=0.0,ynorm=0.0,znorm=0.0; |
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| | | /*find normal of the vertex as sum of all the normals of the triangles surrounding it. */ |
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| | | for(i=0;i<vtx->tristar_no;i++){ |
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| | | xnorm+=vtx->tristar[i]->xnorm; |
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| | | ynorm+=vtx->tristar[i]->ynorm; |
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| | | znorm+=vtx->tristar[i]->znorm; |
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| | | } |
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| | | /*normalize*/ |
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| | | norml=sqrt(xnorm*xnorm+ynorm*ynorm+znorm*znorm); |
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| | | xnorm/=norml; |
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| | | ynorm/=norml; |
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| | | znorm/=norml; |
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| | | /*calculate ddp, perpendicular displacement*/ |
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| | | ddp=xnorm*(vtx->x-vtx_old->x)+ynorm*(vtx->y-vtx_old->y)+znorm*(vtx->z-vtx_old->z); |
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| | | /*calculate dE*/ |
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| | | // printf("ddp=%e",ddp); |
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| | | return vesicle->tape->F*ddp; |
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| | | |
|---|
| | | } |
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| | | |
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| | | void stretchenergy(ts_vesicle *vesicle, ts_triangle *triangle){ |
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| | | triangle->energy=vesicle->tape->xkA0/2.0*pow((triangle->area/vesicle->tlist->a0-1.0),2); |
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| | | } |
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