Matrixr edundant rows removal

I have this matrix: if two or more rows have the same first element, I want to keep only one of them

[ 0.93178465908684446928710074968855, -51.935229283138453086135436847359]

[ 0.22010754397902585905527489863535, 183.86152484784865583467899346115]

[ 0.70067697106846131579942122891388, 220.50586079939492722588263304992]

[ 0.39854749521549824161398289625791, -123.05156509529288636747906602897]

[ 0.84281396964448855914703169574105, -123.25794263558350273782337915136]

[ 0.055796871633806027844183498033979, -65.302512205148103987813108620342]

[ 0.22010754397902585905527489863535, 183.86152592899225091194324659587]

[ 0.22010754397902585905527489863535, 183.86152592899225091194324659587]

[ 0.70067697106846131579942122891388, -139.49413421794328676585602641615]

[ 0.22010754397902585905527489863535, -176.1384735539390731815390671223]

Answer 1

[Paolo]

 newmatrix = oldmatrix(find(uniquetol(oldmatrix(:,1))),:)

[Mohammad Farhat]

thanks, x being what?

[Paolo]

Oops, I had called the matrix x in my workspace. Fixed. If the answer has solved the problem please accept it.

[Mohammad Farhat]

"Error using uniquetol Input A must be a real full matrix of type single or double."

[Paolo]

 x = [ 0.93178465908684446928710074968855, -51.935229283138453086135436847359
0.22010754397902585905527489863535, 183.86152484784865583467899346115
0.70067697106846131579942122891388, 220.50586079939492722588263304992
0.39854749521549824161398289625791, -123.05156509529288636747906602897
0.84281396964448855914703169574105, -123.25794263558350273782337915136
0.055796871633806027844183498033979, -65.302512205148103987813108620342
0.22010754397902585905527489863535, 183.86152592899225091194324659587
0.22010754397902585905527489863535, 183.86152592899225091194324659587
0.70067697106846131579942122891388, -139.49413421794328676585602641615
0.22010754397902585905527489863535, -176.1384735539390731815390671223]

 newmatrix = x(find(uniquetol(x(:,1))),:)

 newmatrix =

    0.9318  -51.9352
    0.2201  183.8615
    0.7007  220.5059
    0.3985 -123.0516
    0.8428 -123.2579
    0.0558  -65.3025

[Mohammad Farhat]

worked,thanks