Remove add_row function from Matrix

[rspencer01]

I am really not a fan of adding rows to matrices for three reasons:

• Complexity: this clones the entire matrix every time just to add a single row
• Clarity: it is very unclear why you should be able to add an arbitrary length row to a matrix with no rows and no columns. The 0 x 0 matrix should not be a special case (it is after all still a linear map from the 0D vector space to itself).
• Necessity: you should be able to just use a n x m matrix and keep track of how many rows you have set. If you are really only interested in a list of vectors, this can also be kept as a [Vec<i64>] or a Vec<Vec<i64>> (note a list of vectors is conceptually different from a matrix)

Temperely-Lieb-Jantzen/src/matrix.rs

Lines 94 to 115 in 63abdc2

	pub fn add_row(&self, v: Vec<i64>) -> Matrix {
	let mut ans: Matrix;
	if self.data.len() == 0 {
	ans = Matrix::new(1, v.len());
	for i in 0..v.len() {
	ans[(0, i)] = v[i];
	}
	} else {
	assert!(v.len() == self.cols);
	ans = Matrix::new(self.rows + 1, self.cols);
	for i in 0..self.rows + 1 {
	for j in 0..self.cols {
	if i < self.rows {
	ans[(i, j)] = self.data[i * self.cols + j];
	} else {
	ans[(i, j)] = v[j];
	}
	}
	}
	}
	return ans;
	}