0="return Math.exp(-7+0.4*group.getLength())/(1+Math.exp((-7)+0.4 group.getLength()));"
1="return Math.exp(-10+0.5*group.getLength())/(1+Math.exp((-10)+0.5* group.getLength())); "
2="return Math.exp(-8.9+0.3*group.getLength())/(1+Math.exp((-8.9)+0.3* group.getLength()));"
3="return Math.exp(-8.3+0.2*group.getLength())/(1+Math.exp((-8.3)+0.2* group.getLength()));"
4="return Math.exp(-5.7+0.2*group.getLength())/(1+Math.exp((-5.7)+0.2* group.getLength()));"


