GPT_LINE

typedef struct {
    int varnum;            /* ID number of variable to plot */
    char title[MAXTITLE];  /* key or legend title */
    char formula[128];     /* expression to plot (rather than data) */
    char style[16];        /* lines, points, etc. */
    char scale[8];         /* string representation of scale factor */
    int yaxis;             /* 1 for left, 2 for right */
    int type;              /* 1, 2, ... (color) */
    int width;             /* default 1, could be bigger */
    int ncols;             /* number of data columns (0 for formula) */
} GPT_LINE;

PLOT_LABEL_TEXT_LEN

#define PLOT_LABEL_TEXT_LEN 31

enum gp_just_codes

typedef enum {
    GP_JUST_LEFT,
    GP_JUST_CENTER,
    GP_JUST_RIGHT
} gp_just_codes;

GPT_LABEL

typedef struct {
    char text[PLOT_LABEL_TEXT_LEN + 1]; 
    double pos[2];
    int just;
} GPT_LABEL;

GPT_SPEC

typedef struct {
    FILE *fp;
    char fname[MAXLEN];        /* for gui purposes */
    PlotType code;             /* to deal with FREQ, FCASTERR... */
    GptFlags flags;            /* bitwise OR of options */
    FitType fit;               /* type of fitted line shown */
    int nobs;                  /* number of observations */
    int okobs;                 /* number of fully valid observations */
    char xvarname[MAXDISP];    /* name of x variable */
    char yvarname[MAXDISP];    /* name of y variable */
    char titles[4][MAXTITLE];  /* main, x, y, y2 */
    double range[3][2];        /* axis range specifiers */
    char keyspec[MAXTITLE];    /* position of key (or none) */
    char xtics[16];            /* x-axis tic marks */
    char mxtics[4];            /* minor tics */
    char termtype[MAXTITLE];   /* gnuplot "term" setting */
    int n_lines;               /* number of lines */
    int xzeroaxis;             /* show x == 0 (1) or not (0) */
    float boxwidth;            /* when using box style for frequency plots */
    GPT_LINE *lines;           /* details on individual lines */
    char **literal;            /* additional commands */
    int n_literal;             /* number of the above */
    double *data;              /* data to plot */
    char **markers;            /* data-point markers (not always present) */
    int n_markers;             /* number of such markers */
    GPT_LABEL labels[MAX_PLOT_LABELS];  /* textual labels written onto graph */
    int *reglist;              /* regression list for X-Y plot with fitted line */
    gretl_matrix *b_ols;       /* coeffs for linear fit */
    gretl_matrix *b_quad;      /* coeffs for quadratic fit */
    gretl_matrix *b_inv;       /* coeffs for inverse fit */
    char *labeled;             /* for GUI use */
    void *ptr;                 /* for GUI use */
} GPT_SPEC;

plotspec_new ()

GPT_SPEC*   plotspec_new                    (void);

plotspec_destroy ()

void        plotspec_destroy                (GPT_SPEC *spec);

plotspec_label_init ()

void        plotspec_label_init             (GPT_LABEL *lbl);

Initializes the label.

plotspec_add_line ()

int         plotspec_add_line               (GPT_SPEC *spec);

plotspec_print ()

int         plotspec_print                  (const GPT_SPEC *spec,
                                             FILE *fp);

plotspec_add_fit ()

int         plotspec_add_fit                (GPT_SPEC *spec,
                                             FitType f);

print_auto_fit_string ()

void        print_auto_fit_string           (FitType fit,
                                             FILE *fp);