# new bmatrix environment

I need to define a new environment which is exactly like

\begin{bmatrix*}[cc]\end{bmatrix*}


environment but I want to replace [cc] with {cc} in the new environment. How can I do that?

The reason I need this is that I have a very large file where I used the array environment for typesetting matrices. I want to use the bmatrix* environment which is from the mathtool package, because it has nicer typesetting; however it uses [cc] instead of {cc}.

• Could you please add some background information on why you want to define such a new environment and what yourput you would expect? – leandriis Oct 22 '19 at 18:20
• Please see edits – Yasi Oct 22 '19 at 18:23
• the [ in [cc] do not make the [ in the output, they are marking an optional argument, like [a4paper] are you looking for \begin{matrix} ? the b in bmatrix is for brackets ie [...] in the output. – David Carlisle Oct 22 '19 at 18:23
• I guess \begin{bmatrix*} is different from \begin{bmatrix} – Yasi Oct 22 '19 at 18:24
• @Yasi I know it comes from mathtools but you should have put that in the question (preferably with a test document) rather than rely on people to guess. So is "use matrix*" the answer that you need? – David Carlisle Oct 22 '19 at 18:30

the bmatrix* environment is from mathtools the b denotes brackets and puts [..] in the output.
You are apparently looking for matrix* which uses no delimiters, or Bmatrix* which uses {...}
Your description of the question as replacing [cc] by {cc} made the question hard to answer as the [ in [cc] is denoting an optional argument, unrelated to the use of brackets in the output, but this was clarified in comments.
• @Yasi ??? this is the answer to the clarified question, isn't it? (the original question, as still in your question post, has no answer as you did not say what output you wanted, just that you wanted to replace the legal syntax [cc] by the syntax error {cc} so I (and I think others) had no idea what you actually wanted to achieve) – David Carlisle Oct 22 '19 at 19:04