How to set depth and level in MakeCKKSPackedPlaintext()

Library Questions
1

I try to use MakeCKKSPackedPlaintext(data, int depth, int level,…) to encode the data in a special level. But the function has another parameter “depth”. How to set depth?

For example:
CCParams parameters;
parameters.SetMultiplicativeDepth(20);
cc = GenCryptoContext(parameters);

vector input(1024, 1.0);

// Now I want to encode the input in level 18! How to set the second parameter “depth”. I cannot find the description of “depth”. Set depth to 20 or 1?
Plaintext input_pt = cc->MakeCKKSPackedPlaintext(input, 20, 18, nullptr, slots);
or
Plaintext input_pt = cc->MakeCKKSPackedPlaintext(input, 1, 18, nullptr, slots);

3

The documentation is a little bit confusing (not updated). The first parameter depth, which is now called noiseScaleDeg, is the degree of the CKKS scaling factor. In most cases, it should be 1 unless you need to encode a plaintext with a square of the scaling factor or a higher degree. The level specifies how many computation levels have already been "consumed`. In your case, for a depth of 20, you are saying 18 levels have already been used and you have two more multiplicative levels left. The ciphertext in this case will be much smaller than a fresh ciphertext (at level 0).