# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/.+{x\=([0-9\.]+)\s*y\=([0-9\.]+).+/($1, $2)/gm;t' <<< "0x0000023646b21750 {x=0.74999899999999997 y=0.91666399999999992 index=69 ...}"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html