Can not use different number of nodes for BicubicSplines

[Jean1995]

It looks like the program crashes if I use different nodes for different dimensions.

For example, this code works:

auto def = cubic_splines::BicubicSplines<double>::Definition(); def.f = func; def.axis[0] = std::make_unique<cubic_splines::ExpAxis<double>>(1., 1e7, (size_t)10); def.axis[1] = std::make_unique<cubic_splines::LinAxis<double>>(0., 1, (size_t)10);

while this one crashes
auto def = cubic_splines::BicubicSplines<double>::Definition(); def.f = func; def.axis[0] = std::make_unique<cubic_splines::ExpAxis<double>>(1., 1e7, (size_t)10); def.axis[1] = std::make_unique<cubic_splines::LinAxis<double>>(0., 1, (size_t)20);

with the error message

Assertion failed: (row >= 0 && row < rows() && col >= 0 && col < cols()), function operator(), file /usr/local/include/eigen3/Eigen/src/Core/DenseCoeffsBase.h, line 367.

I've been building CubicInterpolation in DEBUG mode.