persona.nome='Marco'

persona = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

    nome: 'Marco'

persona.cognome='Caliari'

persona = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

       nome: 'Marco'
    cognome: 'Caliari'

persona.age=35

persona = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

       nome: 'Marco'
    cognome: 'Caliari'
        age: 35

persona.matrice=[1,2;3,4]

persona = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

       nome: 'Marco'
    cognome: 'Caliari'
        age: 35
    matrice: [2×2 double]

persona.cognome

ans =

    'Caliari'

help struct
 <strong>struct</strong> Create or convert to structure array.
    S = <strong>struct</strong>('field1',VALUES1,'field2',VALUES2,...) creates a
    structure array with the specified fields and values.  The value
    arrays VALUES1, VALUES2, etc. must be cell arrays of the same
    size, scalar cells or single values.  Corresponding elements of the
    value arrays are placed into corresponding structure array elements.
    The size of the resulting structure is the same size as the value
    cell arrays or 1-by-1 if none of the values is a cell.
 
    <strong>struct</strong>(OBJ) converts the object OBJ into its equivalent
    structure.  The class information is lost.
 
    <strong>struct</strong>([]) creates an empty structure.
 
    To create fields that contain cell arrays, place the cell arrays
    within a VALUE cell array.  For instance,
      s = struct('strings',{{'hello','yes'}},'lengths',[5 3])
    creates the 1-by-1 structure
       s = 
          strings: {'hello'  'yes'}
          lengths: [5 3]
 
    Example
       s = struct('type',{'big','little'},'color','red','x',{3 4})
 
    See also <a href="matlab:help isstruct">isstruct</a>, <a href="matlab:help setfield">setfield</a>, <a href="matlab:help getfield">getfield</a>, <a href="matlab:help fieldnames">fieldnames</a>, <a href="matlab:help orderfields">orderfields</a>, 
    <a href="matlab:help isfield">isfield</a>, <a href="matlab:help rmfield">rmfield</a>, <a href="matlab:help deal">deal</a>, <a href="matlab:help substruct">substruct</a>, <a href="matlab:help struct2cell">struct2cell</a>, <a href="matlab:help cell2struct">cell2struct</a>.

    <a href="matlab:doc struct">Reference page for struct</a>
    <a href="matlab:matlab.internal.language.introspective.overloads.displayOverloads('struct')">Other functions named struct</a>

persona.cognome

ans =

    'Caliari'

x=linspace(0,1,11);
y=cos(x);
xx=linspace(0,1,21);
yy=spline(x,y,xx);
plot(x,y,'*',xx,yy)
plot(x,y,'*',xx,yy,'-o')
pp=spline(x,y)

pp = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

      form: 'pp'
    breaks: [1×11 double]
     coefs: [10×4 double]
    pieces: 10
     order: 4
       dim: 1

pp.breaks

ans =

  Columns 1 through 4

         0    0.1000    0.2000    0.3000

  Columns 5 through 8

    0.4000    0.5000    0.6000    0.7000

  Columns 9 through 11

    0.8000    0.9000    1.0000

pp.coefs

ans =

    0.0214   -0.5035    0.0002    1.0000
    0.0214   -0.4971   -0.0999    0.9950
    0.0422   -0.4907   -0.1987    0.9801
    0.0569   -0.4780   -0.2955    0.9553
    0.0726   -0.4609   -0.3894    0.9211
    0.0871   -0.4392   -0.4794    0.8776
    0.1011   -0.4130   -0.5646    0.8253
    0.1131   -0.3827   -0.6442    0.7648
    0.1275   -0.3488   -0.7174    0.6967
    0.1275   -0.3105   -0.7833    0.6216

a=pp.coefs(1,:)

a =

    0.0214   -0.5035    0.0002    1.0000

plot(x,y,'*',xx,yy,'-o',xx,a(1)*xx.^3+a(2)*xx.^2+a(3)*xx+a(4))
A=pp.coefs;
x=pp.breaks;
mkpp(x,A)

ans = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

      form: 'pp'
    breaks: [1×11 double]
     coefs: [10×4 double]
    pieces: 10
     order: 4
       dim: 1

b=pp.coefs(11,:);
{Index in position 1 exceeds array bounds
(must not exceed 10).
} 
b=pp.coefs(10,:);
plot(x,y,'*',xx,yy,'-o',xx,b(1)*xx.^3+b(2)*xx.^2+b(3)*xx+b(4))
plot(x,y,'*',xx,yy,'-o',xx,b(1)*(xx-x(10)).^3+b(2)*(xx-x(10)).^2+b(3)*(xx-x(10))+b(4))
help spline
 <strong>spline</strong> Cubic spline data interpolation.
    PP = <strong>spline</strong>(X,Y) provides the piecewise polynomial form of the 
    cubic spline interpolant to the data values Y at the data sites X,
    for use with the evaluator PPVAL and the spline utility UNMKPP.
    X must be a vector.
    If Y is a vector, then Y(j) is taken as the value to be matched at X(j), 
    hence Y must be of the same length as X  -- see below for an exception
    to this.
    If Y is a matrix or ND array, then Y(:,...,:,j) is taken as the value to
    be matched at X(j),  hence the last dimension of Y must equal length(X) --
    see below for an exception to this.
 
    YY = <strong>spline</strong>(X,Y,XX) is the same as  YY = PPVAL(<strong>spline</strong>(X,Y),XX), thus
    providing, in YY, the values of the interpolant at XX.  For information
    regarding the size of YY see PPVAL.
 
    Ordinarily, the not-a-knot end conditions are used. However, if Y contains
    two more values than X has entries, then the first and last value in Y are
    used as the endslopes for the cubic spline.  If Y is a vector, this
    means:
        f(X) = Y(2:end-1),  Df(min(X))=Y(1),    Df(max(X))=Y(end).
    If Y is a matrix or N-D array with SIZE(Y,N) equal to LENGTH(X)+2, then
    f(X(j)) matches the value Y(:,...,:,j+1) for j=1:LENGTH(X), then
    Df(min(X)) matches Y(:,:,...:,1) and Df(max(X)) matches Y(:,:,...:,end).
 
    Example:
    This generates a sine-like spline curve and samples it over a finer mesh:
        x = 0:10;  y = sin(x);
        xx = 0:.25:10;
        yy = spline(x,y,xx);
        plot(x,y,'o',xx,yy)
 
    Example:
    This illustrates the use of clamped or complete spline interpolation where
    end slopes are prescribed. In this example, zero slopes at the ends of an 
    interpolant to the values of a certain distribution are enforced:
       x = -4:4; y = [0 .15 1.12 2.36 2.36 1.46 .49 .06 0];
       cs = spline(x,[0 y 0]);
       xx = linspace(-4,4,101);
       plot(x,y,'o',xx,ppval(cs,xx),'-');
 
    Class support for inputs x, y, xx:
       float: double, single
 
    See also <a href="matlab:help interp1">interp1</a>, <a href="matlab:help pchip">pchip</a>, <a href="matlab:help ppval">ppval</a>, <a href="matlab:help mkpp">mkpp</a>, <a href="matlab:help unmkpp">unmkpp</a>.

    <a href="matlab:doc spline">Reference page for spline</a>

diag([1,2,3,4])+diag([5,6,7],1)+diag([8,9,10],-1)

ans =

     1     5     0     0
     8     2     6     0
     0     9     3     7
     0     0    10     4

spdiags([[1;2;3;4],[5;6;7;NaN],[NaN;8;9;10]],[0,1,-1],4,4)

ans =

   (1,1)        1
   (2,1)      NaN
   (1,2)        6
   (2,2)        2
   (3,2)        8
   (2,3)        7
   (3,3)        3
   (4,3)        9
   (3,4)      NaN
   (4,4)        4

full(spdiags([[1;2;3;4],[5;6;7;NaN],[NaN;8;9;10]],[0,1,-1],4,4))

ans =

     1     6     0     0
   NaN     2     7     0
     0     8     3   NaN
     0     0     9     4

full(spdiags([[1;2;3;4],[NaN;5;6;7],[8;9;10;NaN]],[0,1,-1],4,4))

ans =

     1     5     0     0
     8     2     6     0
     0     9     3     7
     0     0    10     4

spdiags([[1;2;3;4],[NaN;5;6;7],[8;9;10;NaN]],[0,1,-1],4,4)

ans =

   (1,1)        1
   (2,1)        8
   (1,2)        5
   (2,2)        2
   (3,2)        9
   (2,3)        6
   (3,3)        3
   (4,3)       10
   (3,4)        7
   (4,4)        4

spdiags([[1;2;0;4],[NaN;5;6;7],[8;9;10;NaN]],[0,1,-1],4,4)

ans =

   (1,1)        1
   (2,1)        8
   (1,2)        5
   (2,2)        2
   (3,2)        9
   (2,3)        6
   (4,3)       10
   (3,4)        7
   (4,4)        4

spdiags([[1;2;3;4],[NaN;5;6;7],[8;9;10;NaN]],[0,1,-1],4,4)

ans =

   (1,1)        1
   (2,1)        8
   (1,2)        5
   (2,2)        2
   (3,2)        9
   (2,3)        6
   (3,3)        3
   (4,3)       10
   (3,4)        7
   (4,4)        4

x = rand (1, 4);
y = rand (1, 4);
spline (x, y)

ans = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

      form: 'pp'
    breaks: [0.1270 0.8147 0.9058 0.9134]
     coefs: [3×4 double]
    pieces: 3
     order: 4
       dim: 1

pp=spline (x, y)

pp = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

      form: 'pp'
    breaks: [0.1270 0.8147 0.9058 0.9134]
     coefs: [3×4 double]
    pieces: 3
     order: 4
       dim: 1

pp1=spline_notaknot(x,y);
pp.coefs-pp1.coefs

ans =

   1.0e-10 *

   -0.0034    0.0023   -0.0006         0
   -0.0171   -0.0011    0.0003         0
   -0.5002    0.0364   -0.0003         0

spline_notaknot(1,2)
{Array indices must be positive integers or logical values.

Error in <a href="matlab:matlab.internal.language.introspective.errorDocCallback('spline_notaknot', '/home/accounts/personale/clrmrc90/aa1920/calcolo_numerico2/spline_notaknot.m', 13)" style="font-weight:bold">spline_notaknot</a> (<a href="matlab: opentoline('/home/accounts/personale/clrmrc90/aa1920/calcolo_numerico2/spline_notaknot.m',13,0)">line 13</a>)
d0 = [h(2:n - 3) / 6; (h(n-2)-h(n-1))/6; 0];
} 
spline(1,2)
{Error using <a href="matlab:matlab.internal.language.introspective.errorDocCallback('chckxy', '/usr/local/MATLAB/R2018b/toolbox/matlab/polyfun/private/chckxy.m', 42)" style="font-weight:bold">chckxy</a> (<a href="matlab: opentoline('/usr/local/MATLAB/R2018b/toolbox/matlab/polyfun/private/chckxy.m',42,0)">line 42</a>)
There should be at least two data points.

Error in <a href="matlab:matlab.internal.language.introspective.errorDocCallback('spline', '/usr/local/MATLAB/R2018b/toolbox/matlab/polyfun/spline.m', 53)" style="font-weight:bold">spline</a> (<a href="matlab: opentoline('/usr/local/MATLAB/R2018b/toolbox/matlab/polyfun/spline.m',53,0)">line 53</a>)
[x,y,sizey,endslopes] = chckxy(x,y);
} 
spline_notaknot([1,2],[2,4])
{Array indices must be positive integers or logical values.

Error in <a href="matlab:matlab.internal.language.introspective.errorDocCallback('spline_notaknot', '/home/accounts/personale/clrmrc90/aa1920/calcolo_numerico2/spline_notaknot.m', 13)" style="font-weight:bold">spline_notaknot</a> (<a href="matlab: opentoline('/home/accounts/personale/clrmrc90/aa1920/calcolo_numerico2/spline_notaknot.m',13,0)">line 13</a>)
d0 = [h(2:n - 3) / 6; (h(n-2)-h(n-1))/6; 0];
} 
spline([1,2],[2,4])

ans = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

      form: 'pp'
    breaks: [1 2]
     coefs: [2 2]
    pieces: 1
     order: 2
       dim: 1

ppder
{Undefined function or variable 'ppder'.
} 
diary 'off'