read obj in matlab
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function obj=read_obj(input_file_name)
[ node_num, face_num, normal_num, order_max ] = obj_size( input_file_name );
[ node_xyz, face_order, face_node, normal_vector, vertex_normal ] = ...
obj_read( input_file_name, node_num, face_num, normal_num, order_max );
obj.xyz=node_xyz;
obj.face_order=face_order;
obj.tri=face_node;
obj.normal=normal_vector;
obj.vertex_normal=vertex_normal;
obj.node_num=node_num;
obj.face_num=face_num;
obj.normal_num=normal_num;
obj.order_max=order_max;
vertex_mean_normal = zeros(3, node_num);
for i = 1:face_num
for j = 1:face_order(i)
node_index = face_node(j,i);
node_normal_index = vertex_normal(j,i);
node_normal = normal_vector(:,node_normal_index);
vertex_mean_normal(:,node_index) = vertex_mean_normal(:,node_index) + node_normal;
end
end
vertex_mean_normal = vertex_mean_normal./repmat(sqrt(sum(vertex_mean_normal.^2)),size(vertex_mean_normal,1),1);
obj.vertex_mean_normal = vertex_mean_normal;
end
function [ node_xyz, face_order, face_node, normal_vector, vertex_normal ] = ...
obj_read ( input_file_name, node_num, face_num, normal_num, order_max )
%*****************************************************************************80
%
% OBJ_READ reads graphics information from a Wavefront OBJ file.
%
% Discussion:
%
% It is intended that the information read from the file can
% either start a whole new graphics object, or simply be added
% to a current graphics object via the '<<' command.
%
% This is controlled by whether the input values have been zeroed
% out or not. This routine simply tacks on the information it
% finds to the current graphics object.
%
% Example:
%
% # magnolia.obj
%
% v -3.269770 -39.572201 0.876128
% v -3.263720 -39.507999 2.160890
% ...
% v 0.000000 -9.988540 0.000000
% vn 1.0 0.0 0.0
% ...
% vn 0.0 1.0 0.0
%
% f 8 9 11 10
% f 12 13 15 14
% ...
% f 788 806 774
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 27 September 2008
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string INPUT_FILE_NAME, the name of the input file.
%
% Input, integer NODE_NUM, the number of points.
%
% Input, integer FACE_NUM, the number of faces.
%
% Input, integer NORMAL_NUM, the number of normal vectors.
%
% Input, integer ORDER_MAX, the maximum number of vertices per face.
%
% Output, real ( kind = 8 ) NODE_XYZ(3,NODE_NUM), the coordinates of points.
%
% Output, integer FACE_ORDER(FACE_NUM), the number of vertices per face.
%
% Output, integer FACE_NODE(ORDER_MAX,FACE_NUM), the nodes making faces.
%
% Output, real ( kind = 8 ) NORMAL_VECTOR(3,NORMAL_NUM), normal vectors.
%
% Output, integer VERTEX_NORMAL(ORDER_MAX,FACE_NUM), the indices of normal
% vectors per vertex.
%
ierror = 0;
face = 0;
node = 0;
normal = 0;
text_num = 0;
face_node = zeros ( order_max, face_num );
face_order = zeros ( face_num, 1 );
node_xyz = zeros ( 3, node_num );
normal_vector = zeros ( 3, normal_num );
vertex_normal = zeros ( order_max, face_num );
%
% If no file input, try to get one from the user.
%
if ( nargin < 1 )
input_file_name = input ( 'Enter the name of the ASCII OBJ file.' );
if ( isempty ( input_file_name ) )
return
end
end
%
% Open the file.
%
input_file_unit = fopen ( input_file_name, 'r' );
if ( input_file_unit < 0 )
fprintf ( 1, '\\n' );
fprintf ( 1, 'OBJ_READ - Fatal error!\\n' );
fprintf ( 1, ' Could not open the file "%s".\\n', input_file_name );
error ( 'OBJ_READ - Fatal error!' );
return
end
%
% Read a line of text from the file.
%
while ( 1 )
text = fgetl ( input_file_unit );
if ( text == -1 )
break
end
text_num = text_num + 1;
%
% Replace any control characters (in particular, TAB's) by blanks.
%
s_control_blank ( text );
done = 1;
word_index = 0;
%
% Read a word from the line.
%
[ word, done ] = word_next_read ( text, done );
%
% If no more words in this line, read a new line.
%
if ( done )
continue
end
%
% If this word begins with '#' or '$', then it's a comment. Read a new line.
%
if ( word(1) == '#' || word(1) == '$' )
continue
end
word_index = word_index + 1;
if ( word_index == 1 )
word_one = word;
end
%
% BEVEL
% Bevel interpolation.
%
if ( s_eqi ( word_one, 'BEVEL' ) )
%
% BMAT
% Basis matrix.
%
elseif ( s_eqi ( word_one, 'BMAT' ) )
%
% C_INTERP
% Color interpolation.
%
elseif ( s_eqi ( word_one, 'C_INTERP' ) )
%
% CON
% Connectivity between free form surfaces.
%
elseif ( s_eqi ( word_one, 'CON' ) )
%
% CSTYPE
% Curve or surface type.
%
elseif ( s_eqi ( word_one, 'CSTYPE' ) )
%
% CTECH
% Curve approximation technique.
%
elseif ( s_eqi ( word_one, 'CTECH' ) )
%
% CURV
% Curve.
%
elseif ( s_eqi ( word_one, 'CURV' ) )
%
% CURV2
% 2D curve.
%
elseif ( s_eqi ( word_one, 'CURV2' ) )
%
% D_INTERP
% Dissolve interpolation.
%
elseif ( s_eqi ( word_one, 'D_INTERP' ) )
%
% DEG
% Degree.
%
elseif ( s_eqi ( word_one, 'DEG' ) )
%
% END
% End statement.
%
elseif ( s_eqi ( word_one, 'END' ) )
%
% F V1 V2 V3 ...
% or
% F V1/VT1/VN1 V2/VT2/VN2 ...
% or
% F V1//VN1 V2//VN2 ...
%
% Face.
% A face is defined by the vertices.
% Optionally, slashes may be used to include the texture vertex
% and vertex normal indices.
%
elseif ( s_eqi ( word_one, 'F' ) )
face = face + 1;
vertex = 0;
while ( 1 )
[ word, done ] = word_next_read ( text, done );
if ( done )
break
end
vertex = vertex + 1;
order_max = max ( order_max, vertex );
%
% Locate the slash characters in the word, if any.
%
i1 = ch_index ( word, '/' );
if ( 0 < i1 )
i2 = ch_index ( word(i1+1:end), '/' ) + i1;
else
i2 = 0;
end
%
% Read the vertex index.
%
itemp = s_to_i4 ( word );
face_node(vertex,face) = itemp;
face_order(face) = face_order(face) + 1;
%
% If there are two slashes, then read the data following the second one.
%
if ( 0 < i2 )
itemp = s_to_i4 ( word(i2+1:end) );
vertex_normal(vertex,face) = itemp;
end
end
%
% G
% Group name.
%
elseif ( s_eqi ( word_one, 'G' ) )
%
% HOLE
% Inner trimming loop.
%
elseif ( s_eqi ( word_one, 'HOLE' ) )
%
% L
% A line, described by a sequence of vertex indices.
% Are the vertex indices 0 based or 1 based?
%
elseif ( s_eqi ( word_one, 'L' ) )
%
% LOD
% Level of detail.
%
elseif ( s_eqi ( word_one, 'LOD' ) )
%
% MG
% Merging group.
%
elseif ( s_eqi ( word_one, 'MG' ) )
%
% MTLLIB
% Material library.
%
elseif ( s_eqi ( word_one, 'MTLLIB' ) )
%
% O
% Object name.
%
elseif ( s_eqi ( word_one, 'O' ) )
%
% P
% Point.
%
elseif ( s_eqi ( word_one, 'P' ) )
%
% PARM
% Parameter values.
%
elseif ( s_eqi ( word_one, 'PARM' ) )
%
% S
% Smoothing group.
%
elseif ( s_eqi ( word_one, 'S' ) )
%
% SCRV
% Special curve.
%
elseif ( s_eqi ( word_one, 'SCRV' ) )
%
% SHADOW_OBJ
% Shadow casting.
%
elseif ( s_eqi ( word_one, 'SHADOW_OBJ' ) )
%
% SP
% Special point.
%
elseif ( s_eqi ( word_one, 'SP' ) )
%
% STECH
% Surface approximation technique.
%
elseif ( s_eqi ( word_one, 'STECH' ) )
%
% STEP
% Stepsize.
%
elseif ( s_eqi ( word_one, 'STEP' ) )
%
% SURF
% Surface.
%
elseif ( s_eqi ( word_one, 'SURF' ) )
%
% TRACE_OBJ
% Ray tracing.
%
elseif ( s_eqi ( word_one, 'TRACE_OBJ' ) )
%
% TRIM
% Outer trimming loop.
%
elseif ( s_eqi ( word_one, 'TRIM' ) )
%
% USEMTL
% Material name.
%
elseif ( s_eqi ( word_one, 'USEMTL' ) )
%
% V X Y Z
% Geometric vertex.
%
elseif ( s_eqi ( word_one, 'V' ) )
node = node + 1;
for i = 1 : 3
[ word, done ] = word_next_read ( text, done );
temp = s_to_r8 ( word );
node_xyz(i,node) = temp;
end
%
% VN
% Vertex normals.
%
elseif ( s_eqi ( word_one, 'VN' ) )
normal = normal + 1;
for i = 1 : 3
[ word, done ] = word_next_read ( text, done );
temp = s_to_r8 ( word );
normal_vector(i,normal) = temp;
end
%
% VT
% Vertex texture.
%
elseif ( s_eqi ( word_one, 'VT' ) )
%
% VP
% Parameter space vertices.
%
elseif ( s_eqi ( word_one, 'VP' ) )
%
% Unrecognized keyword.
%
else
end
end
fclose ( input_file_unit );
return
end
function [ node_num, face_num, normal_num, order_max ] = obj_size ( ...
input_file_name )
%*****************************************************************************80
%
% OBJ_SIZE determines sizes of graphics objects in an Alias OBJ file.
%
% Discussion:
%
% The only items of interest to this routine are vertices,
% faces, and normal vectors.
%
% Example:
%
% # magnolia.obj
%
% v -3.269770 -39.572201 0.876128
% v -3.263720 -39.507999 2.160890
% ...
% v 0.000000 -9.988540 0.000000
%
% vn 1.0 0.0 0.0
% ...
% vn 0.0 1.0 0.0
%
% f 8 9 11 10
% f 12 13 15 14
% ...
% f 788 806 774
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 26 September 2008
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string INPUT_FILE_NAME, the input file name.
%
% Output, integer NODE_NUM, the number of points.
%
% Output, integer FACE_NUM, the number of faces.
%
% Output, integer NORMAL_NUM, the number of normal vectors.
%
% Output, integer ORDER_MAX, the maximum face order.
%
ierror = 0;
face_num = 0;
node_num = 0;
normal_num = 0;
order_max = 0;
text_num = 0;
%
% If no file input, try to get one from the user.
%
if ( nargin < 1 )
input_file_name = input ( 'Enter the name of the ASCII OBJ file.' );
if ( isempty ( input_file_name ) )
return
end
end
%
% Open the file.
%
input_file_unit = fopen ( input_file_name, 'r' );
if ( input_file_unit < 0 )
fprintf ( 1, '\\n' );
fprintf ( 1, 'OBJ_SIZE - Fatal error!\\n' );
fprintf ( 1, ' Could not open the file "%s".\\n', input_file_name );
error ( 'OBJ_SIZE - Fatal error!' );
return
end
%
% Read a line of text from the file.
%
while ( 1 )
text = fgetl ( input_file_unit );
if ( text == -1 )
break
end
text_num = text_num + 1;
%
% Replace any control characters (in particular, TABs) by blanks.
%
s_control_blank ( text );
done = 1;
word_index = 0;
%
% Read a word from the line.
%
[ word, done ] = word_next_read ( text, done );
%
% If no more words in this line, read a new line.
%
if ( done )
continue
end
%
% If this word begins with '#' or '$', then it is a comment. Read a new line.
%
if ( word(1) == '#' || word(1) == '$' )
continue
end
word_index = word_index + 1;
if ( word_index == 1 )
word_one = word;
end
%
% F V1 V2 V3 ...
% or
% F V1/VT1/VN1 V2/VT2/VN2 ...
% or
% F V1//VN1 V2//VN2 ...
%
% Face.
% A face is defined by the vertices.
% Optionally, slashes may be used to include the texture vertex
% and vertex normal indices.
%
if ( s_eqi ( word_one, 'F' ) )
face_num = face_num + 1;
vertex = 0;
while ( 1 )
[ word, done ] = word_next_read ( text, done );
if ( done )
break
end
vertex = vertex + 1;
order_max = max ( order_max, vertex );
%
% Locate the slash characters in the word, if any.
%
i1 = ch_index ( word, '/' );
if ( 0 < i1 )
i2 = ch_index ( word(i1+1), '/' ) + i1;
else
i2 = 0;
end
%
% Read the vertex index.
%
itemp = s_to_i4 ( word );
%
% If there are two slashes, then read the data following the second one.
%
if ( 0 < i2 )
itemp = s_to_i4 ( word(i2+1) );
end
end
%
% V X Y Z W
% Geometric vertex.
%
elseif ( s_eqi ( word_one, 'V' ) )
node_num = node_num + 1;
continue
%
% VN
% Vertex normals.
%
elseif ( s_eqi ( word_one, 'VN' ) )
normal_num = normal_num + 1;
continue
end
end
fclose ( input_file_unit );
return
end
function c2 = ch_cap ( c )
%*****************************************************************************80
%
% CH_CAP capitalizes a single character.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 22 November 2003
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, character C, the character to capitalize.
%
% Output, character C2, the capitalized character.
%
if ( 'a' <= c & c <= 'z' )
c2 = c + 'A' - 'a';
else
c2 = c;
end
return
end
function truefalse = ch_eqi ( c1, c2 )
%*****************************************************************************80
%
% CH_EQI is a case insensitive comparison of two characters for equality.
%
% Example:
%
% CH_EQI ( 'A', 'a' ) is TRUE.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 28 July 2000
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, character C1, C2, the characters to compare.
%
% Output, logical TRUEFALSE, is TRUE (1) if the characters are equal.
%
FALSE = 0;
TRUE = 1;
if ( ch_cap ( c1 ) == ch_cap ( c2 ) )
truefalse = TRUE;
else
truefalse = FALSE;
end
return
end
function value = ch_index ( s, c )
%*****************************************************************************80
%
% CH_INDEX is the first occurrence of a character in a string.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 01 May 2004
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string S, the string to be searched.
%
% Input, character C, the character to be searched for.
%
% Output, integer VALUE, the location of the first occurrence of C
% in the string, or 0 if C does not occur.
%
value = 0;
for i = 1 : length ( s )
if ( s(i:i) == c )
value = i;
return
end
end
return
end
function value = ch_is_control ( c )
%*****************************************************************************80
%
% CH_IS_CONTROL is TRUE if C is a control character.
%
% Discussion:
%
% A "control character" has ASCII code <= 31 or 127 <= ASCII code.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 26 September 2008
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, character C, the character to be tested.
%
% Output, logical VALUE, TRUE if C is a control character, and
% FALSE otherwise.
%
if ( c <= 31 || 127 <= c )
value = 1;
else
value = 0;
end
return
end
function truefalse = ch_is_digit ( c )
%*****************************************************************************80
%
% CH_IS_DIGIT returns TRUE if the character C is a digit.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 11 December 2003
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, character C, a character.
%
% Output, integer TRUEFALSE, is TRUE (1) if C is a digit, FALSE (0) otherwise.
%
TRUE = 1;
FALSE = 0;
if ( '0' <= c & c <= '9' )
truefalse = TRUE;
else
truefalse = FALSE;
end
return
end
function digit = ch_to_digit ( c )
%*****************************************************************************80
%
% CH_TO_DIGIT returns the integer value of a base 10 digit.
%
% Example:
%
% C DIGIT
% --- -----
% '0' 0
% '1' 1
% ... ...
% '9' 9
% ' ' 0
% 'X' -1
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 22 November 2003
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, character C, the decimal digit, '0' through '9' or blank
% are legal.
%
% Output, integer DIGIT, the corresponding integer value. If C was
% 'illegal', then DIGIT is -1.
%
if ( '0' <= c & c <= '9' )
digit = c - '0';
elseif ( c == ' ' )
digit = 0;
else
digit = -1;
end
return
end
function v3 = r8vec_cross_product_3d ( v1, v2 )
%*****************************************************************************80
%
% R8VEC_CROSS_PRODUCT_3D computes the cross product of two R8VEC's in 3D.
%
% Discussion:
%
% The cross product in 3D can be regarded as the determinant of the
% symbolic matrix:
%
% | i j k |
% det | x1 y1 z1 |
% | x2 y2 z2 |
%
% = ( y1 * z2 - z1 * y2 ) * i
% + ( z1 * x2 - x1 * z2 ) * j
% + ( x1 * y2 - y1 * x2 ) * k
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 31 October 2005
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, real V1(3), V2(3), the two vectors.
%
% Output, real V3(3), the cross product vector.
%
v3 = zeros ( 3, 1 );
v3(1) = v1(2) * v2(3) - v1(3) * v2(2);
v3(2) = v1(3) * v2(1) - v1(1) * v2(3);
v3(3) = v1(1) * v2(2) - v1(2) * v2(1);
return
end
function s3 = s_cat ( s1, s2 )
%*****************************************************************************80
%
% S_CAT concatenates two strings to make a third string.
%
% Discussion:
%
% MATLAB provides the STRCAT function, which you should
% probably use instead of this function!
%
% s3 = strcat ( s1, s2 )
%
% Although STRCAT does not ignore trailing blanks.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 28 May 2007
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string S1, the "prefix" string.
%
% Input, string S2, the "postfix" string.
%
% Output, string S3, the string made by
% concatenating S1 and S2, ignoring any trailing blanks.
%
l1 = s_len_trim ( s1 );
l2 = s_len_trim ( s2 );
%
% The following line essentially "declares" S3 to be a
% character string. Omitting this line would cause S3
% to be regarded as a numeric array.
%
s3 = '';
%
% Now copy the strings.
%
s3( 1:l1 ) = s1(1:l1);
s3(l1+1:l1+l2) = s2(1:l2);
return
end
function s = s_control_blank ( s )
%*****************************************************************************80
%
% S_CONTROL_BLANK replaces control characters with blanks.
%
% Discussion:
%
% A "control character" has ASCII code <= 31 or 127 <= ASCII code.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 27 September 2008
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input/output, string S, the string to be transformed.
%
s_length = s_len_trim ( s );
for i = 1 : s_length
if ( ch_is_control ( s(i) ) )
s(i) = ' ';
end
end
return
end
function value = s_eqi ( s1, s2 )
%*****************************************************************************80
%
% S_EQI is a case insensitive comparison of two strings for equality.
%
% Example:
%
% S_EQI ( 'Anjana', 'ANJANA' ) is TRUE.
%
% Modified:
%
% 30 April 2004
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string S1, S2, the strings to compare.
%
% Output, logical VALUE, is TRUE if the strings are equal.
%
FALSE = 0;
TRUE = 1;
len1 = length ( s1 );
len2 = length ( s2 );
lenc = min ( len1, len2 );
value = FALSE;
for i = 1 : lenc
c1 = ch_cap ( s1(i) );
c2 = ch_cap ( s2(i) );
if ( c1 ~= c2 )
value = FALSE;
return
end
end
for i = lenc + 1 : len1
if ( s1(i) ~= ' ' )
value = FALSE;
return
end
end
for i = lenc + 1 : len2
if ( s2(i) ~= ' ' )
value = FALSE;
return
end
end
value = TRUE;
end
function len = s_len_trim ( s )
%*****************************************************************************80
%
% S_LEN_TRIM returns the length of a character string to the last nonblank.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 14 June 2003
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string S, the string to be measured.
%
% Output, integer LEN, the length of the string up to the last nonblank.
%
len = length ( s );
while ( 0 < len )
if ( s(len) ~= ' ' )
return
end
len = len - 1;
end
return
end
function ival = s_to_i4 ( s )
%*****************************************************************************80
%
% S_TO_I4 reads an integer value from a string.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 18 November 2003
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string S, a string to be examined.
%
% Output, integer IVAL, the integer value read from the string.
%
sgn = 1;
state = 0;
ival = 0;
i = 0;
while ( i < s_len_trim ( s ) )
i = i + 1;
c = s(i);
if ( state == 0 )
if ( c == ' ' )
elseif ( c == '-' )
state = 1;
sgn = -1;
elseif ( c == '+' )
state = 1;
sgn = +1;
elseif ( '0' <= c & c <= '9' )
state = 2;
ival = c - '0';
else
fprintf ( '\\n' );
fprintf ( 'S_TO_I4 - Fatal error!\\n' );
fprintf ( ' Illegal character %c while in state %d.\\n', c, state );
return;
end
%
% Have read the sign, now expecting the first digit.
%
elseif ( state == 1 )
if ( c == ' ' )
elseif ( '0' <= c & c <= '9' )
state = 2;
ival = c - '0';
else
fprintf ( '\\n' );
fprintf ( 'S_TO_I4 - Fatal error!\\n' );
fprintf ( ' Illegal character %c while in state %d.\\n', c, state );
return
end
%
% Have read at least one digit, expecting more.
%
elseif ( state == 2 )
if ( '0' <= c & c <= '9' )
ival = 10 * ival + c - '0';
else
ival = sgn * ival;
return;
end
end
end
%
% If we read all the characters in the string, see if we're OK.
%
if ( state ~= 2 )
fprintf ( '\\n' );
fprintf ( 'S_TO_I4 - Fatal error!\\n' );
fprintf ( ' Did not read enough information to define an integer!\\n' );
return;
end
ival = sgn * ival;
return
end
function [ r, lchar, ierror ] = s_to_r8 ( s )
%*****************************************************************************80
%
% S_TO_R8 reads an R8 from a string.
%
% Discussion:
%
% This routine will read as many characters as possible until it reaches
% the end of the string, or encounters a character which cannot be
% part of the real number.
%
% Legal input is:
%
% 1 blanks,
% 2 '+' or '-' sign,
% 2.5 spaces
% 3 integer part,
% 4 decimal point,
% 5 fraction part,
% 6 'E' or 'e' or 'D' or 'd', exponent marker,
% 7 exponent sign,
% 8 exponent integer part,
% 9 exponent decimal point,
% 10 exponent fraction part,
% 11 blanks,
% 12 final comma or semicolon.
%
% with most quantities optional.
%
% Example:
%
% S R
%
% '1' 1.0
% ' 1 ' 1.0
% '1A' 1.0
% '12,34,56' 12.0
% ' 34 7' 34.0
% '-1E2ABCD' -100.0
% '-1X2ABCD' -1.0
% ' 2E-1' 0.2
% '23.45' 23.45
% '-4.2E+2' -420.0
% '17d2' 1700.0
% '-14e-2' -0.14
% 'e2' 100.0
% '-12.73e-9.23' -12.73 * 10.0**(-9.23)
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 22 November 2003
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string S, the string containing the
% data to be read. Reading will begin at position 1 and
% terminate at the end of the string, or when no more
% characters can be read to form a legal real. Blanks,
% commas, or other nonnumeric data will, in particular,
% cause the conversion to halt.
%
% Output, real R, the value that was read from the string.
%
% Output, integer LCHAR, the number of characters of S that were used to form R.
%
% Output, integer IERROR, is 0 if no error occurred.
%
s_length = s_len_trim ( s );
ierror = 0;
r = 0.0;
lchar = -1;
isgn = 1;
rtop = 0.0;
rbot = 1.0;
jsgn = 1;
jtop = 0;
jbot = 1;
ihave = 1;
iterm = 0;
while ( 1 )
lchar = lchar + 1;
c = s(lchar+1);
%
% Blank character.
%
if ( c == ' ' )
if ( ihave == 2 )
elseif ( ihave == 6 || ihave == 7 )
iterm = 1;
elseif ( 1 < ihave )
ihave = 11;
end
%
% Comma.
%
elseif ( c == ',' || c == ';' )
if ( ihave ~= 1 )
iterm = 1;
ihave = 12;
lchar = lchar + 1;
end
%
% Minus sign.
%
elseif ( c == '-' )
if ( ihave == 1 );
ihave = 2;
isgn = -1;
elseif ( ihave == 6 )
ihave = 7;
jsgn = -1;
else
iterm = 1;
end
%
% Plus sign.
%
elseif ( c == '+' )
if ( ihave == 1 )
ihave = 2;
elseif ( ihave == 6 )
ihave = 7;
else
iterm = 1;
end
%
% Decimal point.
%
elseif ( c == '.' )
if ( ihave < 4 )
ihave = 4;
elseif ( 6 <= ihave & ihave <= 8 )
ihave = 9;
else
iterm = 1;
end
%
% Exponent marker.
%
elseif ( ch_eqi ( c, 'E' ) || ch_eqi ( c, 'D' ) )
if ( ihave < 6 )
ihave = 6;
else
iterm = 1;
end
%
% Digit.
%
elseif ( ihave < 11 & ch_is_digit ( c ) )
if ( ihave <= 2 )
ihave = 3;
elseif ( ihave == 4 )
ihave = 5;
elseif ( ihave == 6 || ihave == 7 )
ihave = 8;
elseif ( ihave == 9 )
ihave = 10;
end
d = ch_to_digit ( c );
if ( ihave == 3 )
rtop = 10.0 * rtop + d;
elseif ( ihave == 5 )
rtop = 10.0 * rtop + d;
rbot = 10.0 * rbot;
elseif ( ihave == 8 )
jtop = 10 * jtop + d;
elseif ( ihave == 10 )
jtop = 10 * jtop + d;
jbot = 10 * jbot;
end
%
% Anything else is regarded as a terminator.
%
else
iterm = 1;
end
%
% If we haven't seen a terminator, and we haven't examined the
% entire string, go get the next character.
%
if ( iterm == 1 || s_length <= lchar + 1 )
break;
end
end
%
% If we haven't seen a terminator, and we have examined the
% entire string, then we're done, and LCHAR is equal to S_LENGTH.
%
if ( iterm ~= 1 & lchar + 1 == s_length )
lchar = s_length;
end
%
% Number seems to have terminated. Have we got a legal number?
% Not if we terminated in states 1, 2, 6 or 7!
%
if ( ihave == 1 || ihave == 2 || ihave == 6 || ihave == 7 )
ierror = ihave;
fprintf ( 1, '\\n' );
fprintf ( 1, 'S_TO_R8 - Fatal error!\\n' );
fprintf ( 1, ' IHAVE = %d\\n', ihave );
error ( 'S_TO_R8 - Fatal error!' );
end
%
% Number seems OK. Form it.
%
if ( jtop == 0 )
rexp = 1.0;
else
if ( jbot == 1 )
rexp = 10.0^( jsgn * jtop );
else
rexp = jsgn * jtop;
rexp = rexp / jbot;
rexp = 10.0^rexp;
end
end
r = isgn * rexp * rtop / rbot;
return
end
function timestamp ( )
%*****************************************************************************80
%
% TIMESTAMP prints the current YMDHMS date as a timestamp.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 14 February 2003
%
% Author:
%
% John Burkardt
%
t = now;
c = datevec ( t );
s = datestr ( c, 0 );
fprintf ( 1, '%s\\n', s );
return
end
function [ word, done ] = word_next_read ( s, done )
%*****************************************************************************80
%
% WORD_NEXT_READ "reads" words from a string, one at a time.
%
% Special cases:
%
% The following characters are considered to be a single word,
% whether surrounded by spaces or not:
%
% " ( ) [ ]
%
% Also, if there is a trailing comma on the word, it is stripped off.
% This is to facilitate the reading of lists.
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 24 September 2005
%
% Author:
%
% John Burkardt
%
% Parameters:
%
% Input, string S, a string, presumably containing words
% separated by spaces.
%
% Input, logical DONE.
% TRUE, if we are beginning a new string;
% FALSE, if we are continuing to process the current string.
%
% Output, string WORD.
% If DONE is FALSE, then WORD contains the "next" word read.
% If DONE is TRUE, then WORD is blank, because there was no more to read.
%
% Output, logical DONE.
% FALSE if another word was read,
% TRUE if no more words could be read.
%
persistent lenc;
persistent next;
tab = char ( 9 );
%
% We "remember" LENC and NEXT from the previous call.
%
% An input value of DONE = TRUE signals a new line of text to examine.
%
if ( done )
next = 1;
done = 0;
lenc = s_len_trim ( s );
if ( lenc <= 0 )
done = 1;
word = ' ';
return
end
end
%
% Beginning at index NEXT, search the string for the next nonblank,
% which signals the beginning of a word.
%
ilo = next;
%
% ...S(NEXT:) is blank. Return with WORD = ' ' and DONE = TRUE.
%
while ( 1 )
if ( lenc < ilo )
word = ' ';
done = 1;
next = lenc + 1;
return
end
%
% If the current character is blank, skip to the next one.
%
if ( s(ilo) ~= ' ' & s(ilo) ~= tab )
break
end
ilo = ilo + 1;
end
%
% ILO is the index of the next nonblank character in the string.
%
% If this initial nonblank is a special character,
% then that's the whole word as far as we're concerned,
% so return immediately.
%
if ( s(ilo) == '"' | ...
s(ilo) == '(' | ...
s(ilo) == ')' | ...
s(ilo) == '' | ...
s(ilo) == '' | ...
s(ilo) == '[' | ...
s(ilo) == ']' )
word = s(ilo);
next = ilo + 1;
return
end
%
% Now search for the last contiguous character that is not a
% blank, TAB, or special character.
%
next = ilo + 1;
while ( next <= lenc )
if ( s(next) == ' ' )
break;
elseif ( s(next) == tab )
break;
elseif ( s(next) == '"' )
break;
elseif ( s(next) == '(' )
break;
elseif ( s(next) == ')' )
break;
elseif ( s(next) == '' )
break;
elseif ( s(next) == '' )
break;
elseif ( s(next) == '[' )
break;
elseif ( s(next) == ']' )
break;
end
next = next + 1;
end
if ( s(next-1) == ',' )
word = s(ilo:next-2);
else
word = s(ilo:next-1);
end
return
end
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